You will get more for your stuff if you sell on auction for sure..
This also depends on how long you wish to spend doing so.. If you just want to get out fast then put a thread saying selling all items and skills at tt or at least half markup and you will still get a good return but won't have to wait long before you sell it all..
If I had the peds I would offer to take it off your hands if your just going to tt it.. But my advice is to sell as much on the auction, or create a selling thread on PCF, or both..
I wouldn't just throw it all into the tt as it would be a waste..
Gl with your selling.. I may have some extra ped to take a few things off your hands.. at mu of course!!
Just a side question.. what is prompting you to leave?