Brushed Aluminum Finish

how much would you pay to change a "silver powder finish" color to a "brushed aluminum finish" ?

I got a local price for 75 bucks a piece, 300 total for the set of four including clear coat.

and what is the process ? do they strip the original silver paint and clear coat ? or do they just strip the clear coat and brush the original silver paint then apply a new coat of clearcoat ?

I believe the would either sand blast the silver off and then sand the it ruff working your way up to a higher grade sandpaper and since you want it a brushed look 
they would clear it rather than polishing it..my guess :-\

maybe you should ask the shop how exactly they plan on doing it... the true way to get THE BEST brushed finish is to actually polish the part, and then scuff it... this way you're starting with what is essentially a uniformly smooth and perfect surface to "brush." Suffice to say, I'd assume that price precludes them doing it that way... so then it's more important to ask them how they get their brushed finish