You’ve probably seen them around once or twice, or read about them online. Green bag dumpsters are a new trend in junk removal that a lot of homeowners and business owners are embracing. It’s not so difficult to see why they are popular. These “dumpster in a bag” products are cheaper than actual dumpsters and a lot more portable. You can put them just about anywhere and fill them up with junk or debris.

Once they are full, you can call the associated trash service for on-demand waste removal service. From renovations and building jobs to spring cleaning projects, green bag dumpsters seem like a convenient option.

However, the fact is that there are some sizable disadvantages to dumpster bags. A dumpster in a bag might look like a convenient bargain option from afar, but you will typically get more value for your money by renting a mini dumpster. Here are five reasons why:

• Dumpster bags are extremely small

Dumpster bags are limited in size. Typically, you won’t find a dumpster bag with a capacity larger than three cubic yards. In comparison, a mini dumpster usually accommodates between 10 and 12 cubic yards of waste. If you need a larger capacity than that, many dumpster companies also offer bins that are 20, 30, or 40 cubic yards in size.

The sizing limitations of a green bag dumpster aren’t a massive problem if you are doing a one-room cleanout, or if you need a place to toss yard waste after a landscaping project. For most projects, though, three cubic yards is just not enough space. Sure, you could buy four dumpster bags to give yourself the same amount of capacity you’d have with a mini dumpster. If you go that route, though, expect the costs to add up. Not only do you need to buy four individual dumpster bags, but you will also pay a separate waste removal fee for each of them. In the vast majority of cases, you will end up paying more per cubic yard than you would for a more traditional dumpster rental.

• Green bag dumpsters are no good for larger items

What are you planning to put in your dumpster bag? If your plans involve any larger items—such as couches, mattresses, appliances, or TVs—you will probably need to spring for a traditional dumpster. Between the size limitations of your bag dumpster and the fact that the sides don’t have the rigidity to prevent items from spilling out, you’ll have a lot of trouble fitting any bigger items into the bag (or making them stay there). If your item can’t fit into the relatively modest dimensions of the dumpster bag (typically eight feet long, four feet wide, and two and a half feet high), you will need to find an alternative way to dispose of them. For these reasons, bag dumpsters only really work for smaller junk items or debris pieces.

• You can buy a dumpster bag anywhere (but you can’t always get a junk removal pickup)

Most dumpster rental companies are either local ventures or nationwide companies with local franchise locations. As a result, it’s not so difficult to find a dumpster company that services your area. If you live out in a rural area, you might end up paying a bit more for dumpster delivery and pickup, but you won’t be left with no real options.

Green bag dumpsters, meanwhile, are connected to a nationwide trash service. You can buy these bags anywhere, whether from stores like Home Depot or online retailers like Amazon. The accessibility of the bags themselves, though, isn’t necessarily mirrored by the accessibility of the junk removal service itself. Indeed, the companies that sell bag dumpsters don’t offer pickup services in all areas. In other words, you could end up buying and filling a bag dumpster only to find that you can’t get a junk pickup out where you live.

To avoid this headache, you’d be better off looking for a dumpster rental company that does service your area. Even if you must pay a bit more for pickup and delivery, it’s better to go into the service knowing for sure that you can get junk removal servicing. That last thing you want is to spend a day filling up your bag dumpster, only to find that no one will come to your address to haul the trash away.

• There isn’t as much flexibility

Right now, there aren’t very many companies offering the dumpster in a bag service. That fact could change as the trend continues to grow in popularity. As more companies get into this niche, customers can start to expect more competition, better pricing, and more flexibility. Before the market gets more competitive, though, there isn’t much flexibility to be found—whether in dumpster bag sizing and capacity or in the items that can or cannot be thrown away through one of these services.

By contrast, the dumpster rental industry has a healthy amount of competition that has driven different businesses to offer bargain pricing, different types of service, and a range of attractive perks. For instance, while you can’t typically throw away appliances or electronics in a dumpster bag, you can find dumpster rental companies that accept these items. You’ll also find dumpster rental businesses that offer perks such as green junk removal, where they take your trash to a sorting center and pull out anything that can be recycled or repurposed. This flexibility and variation makes it easy to find a dumpster rental company that suits your needs. Comparatively, your choices are a lot more limited if you decide to go the bag dumpster route.

• You need to place the bags closer to the street

On the surface, it seems like one of the benefits of a green bag dumpster would be the ability to put it just about anywhere you want. After all, these bags are easy to move around and have smaller dimensions than your standard mini dumpster. If you don’t have much driveway space, it can be a relief to work with a smaller container. You might be able to fit the whole thing on the walkway in front of your house, or even on your front lawn.

However, as portable as a bag dumpster is when it is empty, all that portability goes away when you start filling the bag. A full dumpster bag is unwieldy and precarious. Trying to move it can result in the bag ripping open or junk tumbling out over the edges. As such, dumpster bag companies tend to have specific requirements for how close a full bag needs to be to the street. Usually, the requirement is within 18 feet of the road. If you have a long or steep driveway, you are going to struggle to find a spot for the bag that is convenient for you but also acceptable to the junk removal company.

With an actual dumpster, you are only really limited by the dimensions of the bin. This lack of limitations makes it easy to position a dumpster right outside your house, which is a lot better for filling the bin with junk. Especially if you are dealing with large or bulky items, you probably don’t want to have to walk them down to the end of your driveway.

On the surface, it might seem like green bag dumpsters offer convenience, affordability, and an absence of tough logistical planning. In reality, though, these containers are limited in what they can hold and more expensive than they seem. Simply put, in most situations, you would be better off opting for a more traditional dumpster rental.