people like different marbles. i like akro and master, hard to find these days in my price range plus wet mint ones are harder to find. the other old vintage companies are about the same. no more will be made ever from the companies.
marble king and jabo are nice too. the older marble king are nice. the newer ones are ok but are still being produced and as said before they are mostly collected and not played with so there are more mint ones for your collecting pleasure.
the newer runs of jabo just keep getting better and better but there are more nice ones available than the older stuff simply due to the fact that they are made for collectors and not young kids.
vacor, imperial, and all others come next to me.
i couldn't tell a fake if it bit me.
but i like the vintage marbles. there may have been more made but most have been lost and/or damaged so if you can find some of them (akro, mfc, cac, master, master glass, pelt, alley, kokomo, jackson, ravenswood, davis, cairo, heaton, bogard, vitro, higher-end champion, early mk, and the other rarer companies) buy them. in the end they will hold their value and their collectabilty will go up.
just my opinion.