You have a way cool web page I would like to know how you do it.
Those prices you have been quoted, well seems kind of high to me.
I Just bought of ebay about 1 hour ago a 1st ed. Japanese, Wish you were here, with the black shrink with obi sticker and floyd sticker complete with inserts and poster, nearmint for $37.00. Usually a Japanese first edition of the older ones, on red vinyl near mint with obi, will fetch about $130,$160 $175 depending on the lp. Now while you have some very rare items, they are not as rare as these items. I do not beleve.
Back years ago before the internet, it was harder to find these items and they fetched more Cash. Now for instance, I had a animals lp french pressing MINT that took me a month to sell and I got $10.00 for it. The one on pink vinyl french, mint goes for about $20.00 on a regular basis. Japanese animals mint with obi complete with inserts goes for $15.00 to $30.00
I think with your great knowledge of pink floyd items better than mine, I would say you should know the value of your stuff, if unsure just keep checking on eBay for a while, you will soon find out what your lp's sell for.
when and if you sell you need to sell then seperatly to max your cash, as you know many people collect floyd items. I only collect the Japanese stuff. Lets say you list for sale your entire collection and I need only 1 or 2 or your items. I will not bid on this collection, because it is to much cash and troube, but I would bid on the 1 or 2 items I wanted.
I beleve in the long run you make a lot more cash selling items, not collections. People who buy collections buy low to resell.
If you must sell your collection as a whole and want a fair price. I think it will take you some time. You could do a test, you could list this collection on eBay and put a reserve price of something crazy high so it will not sell, and if it did you would be overwhelmed. Then you could see how much intrest this auction generates and how much people are willing to pay. You could relist it a few times. I buy and sell a lot of lp's on eBay. I have a great feedback record. This helps me sell items and generate more cash.
If you need any help or have any other questions just e-mail me.