if you want to do some major dehydrating, then you'll probably need to consider getting an electric dehydrator. canning allows you to make a vegetable/fruit into a different condiment or something (e.g. salsa or jam) so that you'll be able to enjoy in various ways. and by having to make stuff into those types of condiments, you'll use up a lot of product. you can also make pasta sauces, purees, etc., that you'll get to have variety in your pantry, if that's what you desire.
rehydration doesn't work on everything. i'd look at what item you were thinking to preserve, and then decide if it can even rehydrate to a condition where you'll want to eat it. dehyrating carrots, etc. , may allow you to make your own dry-soup mix