I think $20K for a summer is an extremely high estimate. It's possible if you're at the top of the class, but I'm estimating $5K per summer (basically enough to cover my living expenses). I'd rather estimate low on my income and be pleasantly surprised if something better comes up than to estimate high and be blindsided when it doesn't work out that way. Also keep in mind that the $20K COL estimate the schools give is based on 9 months, not 12. If you can make it stretch, that's great, but some of your summer $$ will probably go toward covering costs, not completely to debt payoff.
I'm not sure if Drexel offers work study to their law students. It seems like it would be difficult to do with the co-op program, and I'm not sure if the federal funding for work study is affected because they're not yet accredited. This would be a good question to ask a Drexel admissions staffer.
Personally, I still think Temple is a better option (and not just because that's where I will be
). As I said on a different thread a couple months ago, a lot of Philly lawyers are not happy about the addition of another law school here and I'm not sure how that will impact hiring, even after it becomes accredited. Also, Drexel's focus is still very narrow, so unless you're interested in healthcare law or entrepreneurship law, I'd think very hard about going there.