Can anyone give me ball park figure to have a roll cage installed welded or bolt in?



92'325i/5 w/150k, black,m3 contours/shift knob
94'325ic/5 w/73k, white,supercharger,bbs,supersprint,k&n
97'528i/a w/75k, white, stock
91'300zx 2+2,130k turbo spoiler