Big Ben’s is a must stop. Go to the Allen Park location. They have a new one I haven’t been to, but I believe it doesn’t have much in Silver and Bronze.
Time Travelers in Berkley will have enough Silver and Bronze to make in worthwhile.
Vault of Midnight and Green Brain seem to mostly have newer stuff. I have not been to the Detroit location of VoM yet though.
Stadium Cards and Comics in Ypsi probably has close to 40 long boxes of Bronze, Copper, and Modern books and is a worthwhile stop.
As Sigur mentioned, Plymouth has, or had, two decent shops that would be worth visiting that are nice. Try Compari in downtown Plymouth for pizza and roasted garlic bulbs if you like garlic.
Clawson does have GOB and Warp 9 that are a mile or so from each other, so you can also get a two for one there too.
There are some decent places in the northeastern suburbs. I haven’t been to them in a while, and they have been a bit pricey when did visit them.