Find a way to make quality tables cheaper so more people want them.
I really believe this would make an enormous difference. The market is dominated by low-quality (albeit still several-hundred-dollar) tables. Families that purchase a table that is essentially unplayable get discouraged and then try to sell the thing. Craigslists across the country are full of ads for these cheap tables.
By way of analogy, there are many really good and playable inexpensive guitars out there. Kids can pick up a japanese Fender Strat clone for cheap, and can actually have fun and get GOOD before moving on to the real thing. Cheap foosball tables are frustrating to play, just end up collecting dust, and the potential champions go find another pasttime.