Definitely not bottomed out....just look at prices for prior generation Cayenne Turbos. An 06 Turbo with 100k can be found for $10-15k. Maintenance and repairs are still that of a $130k car. The 2011's have some issues that I believe were resolved for 2012 model year. Make sure to have a PPI done on any car you're looking at and check the maintenance/repair history. They are awesome though, I was real close to buying one before deciding that an X3 35i for half the price was more reasonable for a second car. I plan on upgrading to a Cayenne Turbo or GTS at some point though...
On a side note, make sure it has the options you want. If you aren't familiar with Porsche, there is a laundry list of options and some are more useful/important to have than others. A Turbo build could be anywhere from ~$105k up to ~$160-170k depending on the options. Anything with MSRP in the $130-140k range is going to be pretty loaded. You can look up the build sheet using
https://www.vindecoderz.com/