What are some tips on making money in this hobby?

[mechanicalman]

I believe if you want to buy "big boy cards" (your words, not mine), I think your time and capital will be better invested in places other than cards. In my observation, people can make a ton of money selling stuff they DON'T have passion for. I've heard of many housewives who earn 7 figures selling crap on Amazon because they fill a market need. There is no gap in the market for people re-selling sports cards.

That said, if you're intent on playing the flipping game, I might suggest a different route. Instead of going after the premium quality cards, buy the worst cards of a certain grade (which typically go for a lot less than high end cards) and then price it on eBay at or just below the average prices for HE cards. So, a new, less savvy buyer might see your off-centered Cobb 5 priced below one that just sold at a high from PWCC, and he might think he should snag it. This seemed to the model of Mike Dinero (though I don't see his listings anymore.) Other folks on the board seem to do this is as well, so perhaps there's something to it. I'm speaking only from observation, not experience.