lets say you spend 7500........ 1500 for materials (which prob dont cover everything)
leaves 6K for labor......... at 50 per hour its 120 hours......... its just not enough time for a quality job, neither you or the guy doing the work will be happy..... it wont end well.
that being said, the person/shop performing the work should know better.....beware of someone willing to work cheap, it could be like throwing money away, especially when rust starts creeping out of the nooks and crannys