Theres two ways me thinks.
One in fact is you are a millionaire and use your money to enrich ebay or dealers...but personally I only know one
The other is you have started early enough to have enough records (to either find the one or two re-activated emperor`s new clothes in your collection to play out and / or to sell records you once bought cheap for a much higher nowadays price)
PLUS
and thats the mnain thing IMVHO
you have an ear, go around, listen to different DJ`s, are open for new sounds and impressions, buy blind, take the risk, dig hard, search everywhere, are imaginative, have good contacts, know a lot of fellow collectors, know even more dealers, hustle around, are a part-time dealer, are able to let things go, spend several hrs each day on the net on the look for new stuff CHEAP
I believe the last part is the real truth behind people like Andy Dyson, Mark D, etc ... so to state the old "its a rich mans game, you have to be a millionaire etc" is a lame excuse and most of the time used by people who are too lazy to be as active, to do the same or who are simply just jealous or like to moan in general.
Just my opinion.
(no offence and not intended against anyone taking part in this thread of course)
Marc