Dortmund have struck a balance with when to sell them (at the cost maybe of at least one title the last 8 years, i would guess) and allowing release clauses when needs be; Brighton are gambling with making their very best players nigh impossible to buy except for obscene money. I think their model is really good overall, from scouring to de Zerbi headhunted to replace Potter, the transition to progressive football post Hughton etc, - but they're on a tightrope in terms of how they present themselves to players as a place when you can develop and even compete for some kind of trophy, but also be allowed to move to a top-table club if they offer decent money, so being competitive but also not holding players trapped there.....