I watched this again and, uh....I have the sudden urge to slap Marge upside the head.
In earlier episodes, especially "Seperate Vocations", which aired back when the show was genuinely funny, Marge wasn't acting like a little kid who had his crayons taken away when Lisa was upset/apathetic/worried she might end up like her mom. Compare that to this S22 episode where Marge is a complete jerk. Marge in SV acted like a mom who gave a crap about her daughter and took Lisa's disdain with her trademark mom-ness. Even more disturbing, Lisa didn't even tell Marge how she felt--Marge got the news via second hand from Homer, and without seriously questioning him if he was drunk or not. Then she never even asked Lisa to her face and just acted like an ass on a mere whim. Translation: Marge was actually stupider than Homer!
Not to mention Separate Vocations wasn't filled with filler scenes with Homer buying gas in more and more stupid ways over the course of 4 minutes. It's not like the writers could've had Lisa tell the family to try something a bit more practical...LIKE EBAY, or CRAIGSLIST. (Both of those sites are ripe for satire, er, Zombie Simpsons isn't a satire...my mistake.)