Anything that's salable can realistically be sold. To make your old bike salable, you should probably replace the broken chain and paint over the rusty spots.
If you want to make a little extra money at the craft fair, you'll have to come up with some salable crafts. And if your club's bake sale is going to be a success, you'll all have to contribute enough salable cupcakes and cookies. The difference between something that's salable and something that isn't is that people would realistically want to buy the salable item.