With an eye towards having everything sold by the summer, I’m going to price at under the average used listing according to BrickLink’s guide (with a cursory check on eBay/Amazon/other valuations as well).
e.g., LEGO Castle Giant Chess Set #852293 Used, good condition — $550 or best offer
(BrickLink gives Min Price: US $300.00/Avg Price: US $631.43/Max Price: US $750.00)
I’ll post again with photos and further listings later tonight, have to run now…