I hate to be a downer, but the resale value of warhammer is nothing, and the older models.. even less.
I had over 3000 point armies of Space marines, dark eldar, necrons, imperial guard, tyranids including limited edition and unopened versions of the emporers champion, my the years i collected, about £2500 worth of stuff, all painted pro (not scrub ultramarine type things, I did legeion of the damned ect).
I sold it for 700 the lot, and i had to push it to sell it at that (I only got that cos I threw in over £100 of paint for free)
Im sorry but you just cant say "I spent this much" on something and expect to make it back on a childs game.