The b5m as a roller( no electrics) prob looking at £150, the lrp stuff is top notch, the motor is £72 new, ESC £100, savox servos are spot on too. The older car still has decent speed passion gear in it, so I guess he'd want near £300 for both ( depends on his reserve) . Great starting kits tho by the looks of em. Good luck in the auction.
Just check prices on MB models website. Generally Cheapest place to get spares.
http://www.rccarshop.co.uk/index.php/