It's annoying, but I think that's (Willow and Tara dumping their financial troubles on Buffy) what the writers were going for.

Which sucks because it throws out seasons of characterization on both girls' parts for one season. Though I do think that Buffy did make her own bed. AOL is all over California and they pay people like ten bucks an hour to work the phones so I think Buffy went for the first job she could find without thinking about her other options.