Why is a futon a great value? Buy a well made futon and you get a versatile sofa-sleeper that will be used for years to come. Everything on a futon is interchangable. Tired of the cover or look, get a new one. Your futon Mattress wears out, get a new one. What other piece of furniture can you get that works like this? A good sofa-sleeper can be costly $1000 or more while A well made futon with a decent mattress can cost from $500 and up. The $200 ones are usually poorly made metal or metal wood combinations with thin futon matts. Only a good choice for short term use. They won't last and even if they do, you won't want a cheap futon in your home or apartment. Why would you want to feel the bars on the seat?
The amount you pay for your futon does make a huge difference in how long the futon will last. Wood is stronger than metal and costs more but if something breaks on it you can usually get a part. The mattresss give you your comfort and support. Put a well made innerspring or foam mattress or a thicker more traditional foam and cotton for years of wear. Covers also come in different fabrics and styles, some better made than others. But they can always be upgraded over time.
Do you move a lot? Futons come apart for easy moving and storage. Futons work well in many areas of your home. So, when you move, changing the look by changing the cover is easy and not too expensive. Maybe $50-$150 or more depending on fabric and how well it's made. This is a lot less than recovering a tradtional sleep sofa.
A well made futon is a great value. It gives you a comfortable place to sit in any room. If you need extra sleep space you have it quickly. Buying cheap is not a good value. Select a piece that's nice for years of enjoyable use.