You could categorize the foods by effect, and then put concealment over them. Like, have all the healing things in one place, speed effects, regeneration, and miscellaneous buffs in their own locations, and rank their price by usefulness. That way, you won't know what you're buying, but you know if it costs five crystals, and is in the 'Special' section, it's going to be a Magic Soup or a Hot Borscht or something.
This (excellent!) video makes me wonder two things:
1. Are you using only the music from Aquaria Proper, and is there going to be music for every place? I've always felt like the various bosses' music could be a little... spicier.
2. Do the item and food vendors only have items and foods from Aquaria Proper? Or are there super-secret-brand-new foods and items?