Also, be careful as it is much like crack - a bit moreish.

I did the bulk of my collecting/buying 'as it happened' which obviously made life easier, but...
It can become overwhelming.
I scaled back most of my (non Morrissey) collecting as soon as Japanese 3" CD singles (with all important adapter), German maxi singles, DAT tapes and a whole array of oddities saturated the market on top of already huge variants of pressings.
So, set yourself
realistic goals that suit your budget and mindset.
If you are a completist, then you have a huge task ahead - colour variations, font variations/positioning, promo deviations & variations, stickers/no stickers, mispresses, 10+ versions from different countries et al... it became financially unviable to keep collecting loads of artists when this was the case.
Coupled with dodgy sellers, misinformation, not as described etc...
It all depends on how much importance you place on having ALL of something and how attainable that is as time ticks on.
Buying someone's entire collection would mitigate some of that, but obviously would not be cheap.
Try getting the basic UK set of releases (7s & 12s) and the possibly branch out with interesting versions of the things you already have and see where it takes you.
Best of luck.
Regards,
FWD