[kennethso]

You can’t turn bananas back into seeds and water, just like in real life.

[kennethso]

This post gives you some examples for stocking up resources for alchemy (making off-hands):

Strategy tips

To sum up what that guy said:
Banana: South Beach 3
Tomatoes: White Garden
Sea Berries: Limestone Lagoon 6 (though I think Limestone Lagoon 2 may also be ok)
Ice chilli: Winter Wonderland 4
Snow apples: Winter Wonderland 2

For water you can just get them from South Beach 4
It seems that there is no easy place for getting vials (I could be wrong. I just started playing a few days ago and now I’m at Limestone Lagoon). So crafting from sand may be a better choice. An easier level with sand as the main price will be Golden Fields 2, but as sand is quite plentiful, you can get a lot by repeatedly playing those South Beach Levels.