I'm with @rushbo 100% regards the importance of the neck or lack of when it comes to body material.
Folk have the strangest notions about basswood, poplar, okoume or even pine, thinking them lesser timbers.
Tom Anderson has no problem using basswood bodies for guitars costing £4k. Nor does Ibanez, plenty £2k basswood models from them.
Go for it.
Selling on the neck, pickup and hardware might get you back £40 to £50. Now £80 for under 4BF of alder is a lot of cash but
Stain generally takes a few trial and error sessions.
Poly isn't cheap or that quick.
Polishing takes time.
Add up the time it would take to thickness then plane & square the alder, joint it, cut out the body, router cavities and sand. Even if you paid yorself minimum wage, you won't bring that body in for £80 😀