What exactly was the transmission doing when it triggered the malfunction codes? Shifting erratically? When was it last serviced? Was the bridge seal replaced?

Your original Mechatronic can be rebuilt for about $1000, and will probably fix your issues. Are you adept at repairs, or do you just drop it off and toss them the keys? A trans service with a new pan, seals, and fluid is about #350 thru FCP. Plan on about 2 hours to drop the exhaust and rear trans mount, drain and remove the pan, and remove the mechatronic. Once you get it back, plan on 3 hours to put it all back together and properly fill the tranny. I just did this on an E60 LCI car, and besides being messy, it isnt that hard. There are plenty of DIY out there. Biggest difference is that you'll have to unbolt the front driveshaft to refill the trans