The 2001 GMC Sierra 2500 is available as a 2-door, 3-seat regular side. Starting at $21,914, the 2001 GMC Sierra 2500 SL 4x2 Regular Cab is powered by a 6.0L , 8 -cylinder engine that returns an EPA estimated The top of the line 2001GMCSierra 2500SLT 4x4 Extended Cab , priced at $ 30,756 , is powered by a 6.0L , 8 - cylinder engine that returns an EPA estimated