I have most of the Grapevine singles, all bought at the time of release. I must admit that I never considered for one minute that some of them would achieve any kind of value in the future. So, yes, you have a point there.
If I remember correctly, 1980 was the big year for Grapevine releases, I was 17 years old then and they were the nearest I could get to owning an original, at 85p each, they were affordable and credible (to me, at least). Maybe the Outta Sight releases are the modern equivalent.
Now in my 50's, mortgage paid and with more disposable income, I guess that I am lucky that I'm now in a position to dismiss some new reissues in favour of chasing original vinyl.