wheres best

[miniwolf]

just bought a mini one,had black with white edging bonnet stripes,bye the way its red,mini.....but i now would like some 17" wheels,ive just bought a van for myself,for work,so its my wife that drives it...i dont think shes that bothered,but its buggin me slightly,ecspecially,after lookin at the smart minis on here,so to start off,id like to get a second hand set,i suppose alot of people upgrade,so what type,wheres the best place to try,and how much should i expect to pay,thanks to anyone who can reply..............

[miniwolf]

also,would i get much for the ones i already have,i think 15",with round holes in rather like pepperpot.........