Well guys... I've talked to 3 tranny shops now. Two of them say $2000 fix just based on P0742 and P1811. The third guy was pretty abrupt on the phone, said 'those are bad codes to have' and that he'd need to have a look. I'd guess he'd ask the same or more, but I didn't like his demeanor on the phone so I don't think I'll drop the Olds off there.
One guy I talked to for like 5 mins and he was very helpful. He said I could drive the car another month without worrying about doing more damage or getting stranded. That contradicts what the anti-seafoam guy said on tuesday, but I like his answer better so I'm gonna put off dropping the bread for a while. I'm already looking at $3-4000 in dental and moving expenses right now!
Just another update but please feel free to share any thoughts!