I've had the same mindset for a wee while and decided to do something about it this year. So, all my car kits, WWII stuff and the bigger WNW (which I don't have big enough cabinets to display) went on eBay.
Well, after three months I'd cleared more than 8,000 GBP!!!
Unfortunately I seem to have bought so many books since, that the stash is the same size - just books as well as kits!
Glad to see you've got other scales than just the wee guys in there - nice collection.
Sandy