To some people a 24 inch saw is small while others consider a 16 inch saw large. What do you mean with "small" and how much space do you have?
You are likely to make the best deal in a long term perspective if you figure out how much space it can take up without getting in te way for other operations. Then look for the most solid and well kept secondhand saw you can find that will fit into that amount of space. Secondhand band saws of good quality in decent condition tend to cost roundabout the same regardless of size.
If you lack the time or the skills to do some minor fixes on a secondhand machine you have to accept that your money looses a good deal of leverage. Buying new is the best option to some people so it should not be totally dismissed. Everything depends on what kinds of resources and needs you have.