But it appears they have protected their position in deals which see bright prospects try their luck in first-team football.
Andrew Moran headed to Preston North End for a seven-figure fee on deadline day to end what was almost six years as an Albion player.
He followed Odel Offiah, who made a permanent switch to Deepdale in the summer and has been a regular in their push for the play-offs.
Preston boss Paul Heckingbottom has been speaking about transfer business, the details of which are handled by his vastly-experienced chief executive Peter Ridsdale.
Heckingbottom said: “I think he has been really pleased and impressed with dealing with Brighton, and how easy they were to help us get the deal done.
“If they think it's right for the player and they think we then get a chance to develop that player, they can still keep a share in him if they like.
“Without going into the deals because I don't know that side of it, but that's obviously what the Premier League teams can do as well - keep a share in that player if they think they're going to a club which can help develop him.”
Heckingbottom says clubs like Albion are driving a harder bargain these days with their younger players.
He added: “What you used to get them out for, compared to now, was peanuts.
“What used to cost 100 grand with a sell on is nowhere near that now and that's the difficulty. But we've done well with Odel, now Andy and I think Peter would probably back this up.”
Moran has played in the Championship with Blackburn and Stoke.
He has trained over the last few weeks with Albion and head coach Fabian Hurzeler has spoken about how close he was to making his Premier League squad at the start of the season.
Heckingbottom said: “He knows the league, a really good footballer, good pedigree, people like him and he's a good age.
“He's one we are looking forward to working with, definitely.
“He has got a final pass, understands the game with and without the ball.
“If we can add and keep pushing him to get more goals and tally up his assists, then that's what'll stand out and that's what we hope he can add to us.”
Offiah cost Preston a seven-figure fee last summer when he signed from the Seagulls on a four-year deal.
He had to bide his time in the first few weeks of the season but, following injury to Pol Valentin, regular minutes have come his way at right wing-back.
Offiah, now 23, has spoken of his ambition to return to the Premier League and of his education with the Seagulls.
He said: “I had been there for so long and, when you go through the different coaches in the age groups, you learn so much.
“Obviously, the different managers, even when you're just training and not playing the senior pros that are there like Danny Welbeck - he was really good with the young lads coming through.”