Marc......Yes I'm certainly no expert on prices these days, but doesn't the base on which Northern Soul was built, centre around 'turntable demand'?
Delrays at present is a cult 45 which hasn't fully crossed over, but it's getting there. Try buying one right now.......
Search your price guides and look at others that were given 'a value' and subsequently spiralled to dizzy heights(Tomangoes..now 3k, I think you could get 4!-Hamilton Movement, Rita and the Tiaras and a few more I could mention). Why only 2 weeks ago I called a collector/fan to bag the 7th Ave Aviators on Congress, foolishly selling mine several years ago for 400. I was quoted 900! Is it worth it....no.....but everyone wants it. Thankfully I purchased Frankie Karl on Philtown DJ for 800, which I feel is a bargain at present.
With so many DJ's around the world spinning our beloved genre, the demand has gone up for those 'hot, won't go away' 45's. IMHO