TPE is not always way off. TPE is rarely way off. Sometimes it is being influenced by the cheaters. If you want to sell your player check the TL for similar players and watch how much they sell for, then list your player. If you really have no idea how much your player is worth, list him at $1.
Ok i check this with my team, only 2(!) player in my entire team have a TPE and the TPE from one of them is way off the other is a minute killer with a tpe around 5k and we could een discuss if you could sell them for the maximum price of 60k.
So now lets take a look at the bookmarked player i like to buy, you see the same. A advanced minute killer who runs out from this list and looks like that:
Age: 26
9-7
9-5
9-8
6-8
7-8
5-8
XP: 6
So guess the how much he is worth, i am pretty sure that this is very different from the TPE.