I was busy last days, so a little update:
An ingame friend, 1 level higher, wanted to buy Kraxner - he offered 10T. Even Kraxner is 29 y.o. and ~20% weaker than the average teamquality, I couldn't sell him, he still performs. He played 11 seasons, made some important/goals... I really like this guy, so he played again every game this season - and I think, he is thankful, I keep him...
I also bought 3 new players (one academy-player) - if everything goes well, I'll keep the whole team until Kraxner retires.