Thanks for the explanation but I hate to break it to you - I doubt you'll get a whole heck of a lot of money out of selling what you have. At least not enough to buy the equipment you're looking at unless you buy used. Pennies on the dollar selling your old stuff, if that. IIRC you have a quantity of brass track - you'll get nothing for that. The rest of the track, if you pull it up gently you may get something. Oh yeah - to pull up track that's been glued down, if you used the old mixed white glue and water deal is to just liberally soak it until the track comes up. Been there, done that. Doesn't matter how long it's been down. Don't know about getting it up if you used some caulking material. Some of that is waterproof. I doubt Atlas code 100 (which is what it looks like you have) is that big a need anymore.
Sadly most railroaders when they go to dismantle layouts, unless it was built to do that from the start, end up putting most of that in the scrap bin. W. Allen McClelland was one of the lucky ones when the old V&O was torn down. One section went to a museum, the rest in the scrap heap.
Your best bet is to get what you can from the rolling stock and motive power. That will be your biggest money maker assuming everything's in good shape and has Kadee couplers or equivalent.
There's one possibility that might save you some grief - get hold of somebody that deals in estates and liquidations.