Shocked to read this Kim but totally know and understand where you are coming from, good sound advice from the likes of Andy etc. just to add to answer your original question as to who has the buying power pretty much all the names mentioned, being good pals with JM he's always pretty fair and won't tend to cherry pick, pays a premium for titles he does not have so might be worth a go if you do deside to sell.
I've pretty much moved on all the big ticket items with no regrets really as when I stepped down from the full on DJ thing I simply could not justify sitting on thousands of pounds in records, do I like the music any less because I no longer own it no of course not, at the end of the day it's your choice and if you can remove the emotional attatchment rare soul generates then you will have no problem letting them go so make sure you are ready to sell them difference is I still like to pick up little bits and bobs and having a ball just not spending as much lol which seems to satisfy the collecting bug that pretty much remains with us at various levels.
Regards - Mark.