The Situation Sues -- I Charge $30,000 to Appear in Nightclubs

The Situation charges $30,000 A POP to appear in Vegas nightclubs ... so says the "Jersey Shore" star ... who's now suing a promoter for stiffing him to the tune of $60k.

Sitch filed the suit in Miami, claiming he struck a deal with a promotion company last year to make a total of 3 appearances at Vegas nightclubs Chateau and Gallery by June 30th.

According to the lawsuit, the deal was "pay or play" -- meaning Situation was to get paid the full amount ... even if the club decided not to use him all three times.

Situation claims the club only called him in once before the deadline ... and only paid him $30k.

Now, the "Jersey Shore" star is suing the promotion company for the balance -- $60,000 -- insisting it hasn't held up its end of the bargain.

Calls to the promotion company Diversified Entertainment were not returned.