Did those players had been sold for more than what they bought for?
No they did not.
mailny for the reason, that they don't buy/sell players there, is it very rare that you pay transfer fee at the european basketball. Sometimes ACB teams does, but i am not an expert there.
But in germany we had maybe one transfer the last 5 years, and that was a payment a club had to made since they signed a player who had a contract in germany and just refused to fly there, his agent said his contract is void and organised him another contract - with the problem that the contract wasn't void. Afaik even the player pay the transfer sum to make him eligible for playing
but i can give you example in the NBA where player was traded to a club, who traded them right away most likely cause they expect to get a better player for them or increase the value with the switch?