For the Rotel items the standard advice from me is; check ebay for past sales and maybe watch a few auctions of like items. If your only intent is to sell the pieces, simply list on ebay with a low starting bid and no reserve. You'll get what they are worth minus ebay fees.
As for the Leon pieces, I'd find the MSRP and list them here or at other audio sites for 50% of list. Be prepared to take less though.
As for the Leon pieces, I'd find the MSRP and list them here or at other audio sites for 50% of list. Be prepared to take less though.