If you are up for a road trip, try The Bargain Shop in Jacksonville, NC:
http://bargainshopjack.com/prosite/It has two locations, and a RIDICULOUS selection of old-school games. It is worth going just to see some "Holy Grails" behind glass. Unfortunately, the guy who runs the store has a good idea regarding how much each game is worth; so, you are unlikely to get a really good deal. (He usually charges a little less than the going price on eBay...but you obviously don't have to pay shipping.) On the other hand, this means that you can get some common games for really cheap ($1 to $3). Jacksonville (being a military town) also has a ton of pawn shops that are worth exploring since they also take in a lot of games.
You've mentioned the only places that I can think of in Raleigh. The only other places you might want to try are the flea markets. There are a couple good sellers at the NC State Fair Flea Market, but I have never received a really good deal there. There is a flea market off of I-40 in Alamance County with only one seller, but he has no idea how much any of his games are worth. (He charges $5 for all of them...I am a collector, not a reseller, so I let a lot of his good deals sit there the last time I visited.) Any flea market you can locate in the far eastern and far western part of the state should have at least one seller.
I live in Charlotte, and I get most of my games from the four surrounding flea markets (one off of I-85 north of Charlotte, one off of I-77 just across the SC border, one in Monroe, NC to the east, and one in Dallas, NC to the west). We also have a Goodwill Computer Works store:
http://www.goodwillsp.org/computerworks.htmlwhich always has a solid selection of old-school games. (I think it is the only one in the state.) I check it once every two weeks or so.
I can tell you to avoid the Winston-Salem/Greensboro/High Point area. I lived there for three years, and I never found a place with a reliable stock of old games.
Anyway, good luck and happy hunting!