Welcome to the board, Andrew.
Feel free to post some pictures of your display cabinet -- that sounds pretty cool. Did any stars or HOFers come up through Portland's AAA team? (to post pictures you can either upload them here when replying to a message, or you can use the links from a photobucket-type site).
If I could offer some advice it would be collect what
you like. Some people can afford and prefer high grade cards, some collectors search for mid-grade cards with nice eye appeal, while others collect well-loved beaters and could care less about grading, condition, etc. It's all good.
Regardless of the grade, you will find cards with really good centering selling for premiums. If you are bidding on a card or item and you lose out, be patient -- most likely another one will show up down the road and you will get it for a lower price. Good luck and have fun!
Some helpful links:
http://www.auctionreport.com/
http://www.sportscollectorsdaily.com/
http://www.cardtarget.com/ (great free price tracking site)
http://www.vintagecardprices.com/ (subscription site, but they offer a cheap, one day membership that can help out in a pinch)
And finally, nice choice on the Diamond Stars set. I feel it is somewhat underrated, and I love the art deco style of the artwork. I only have one in my collection, but it was one of the first vintage cards I bought when I got back into collecting in '99 (also my only Hornsby card).
