The likes of Liam Bridcutt, Craig Mackail-Smith and Will Buckley have been linked with moves away from the club after impressive performances in the Championship this season.
However, Poyet is fed up of being asked for too much money for his own transfer targets, particularly British players, and plans to make life equally difficult for his rival bosses.
"I don't think I'm going to be reasonable because when I try to buy, nobody is very reasonable," Poyet said in the Daily Star.
"British players are overrated - they are too expensive for no reason.
"Everybody wants the best British players and that makes you pay too much.
"But when you can go overseas and get a better player for half the money the complaint is there are too many foreigners."