If you're looking to print aluminum replacement parts, you should look at the higher end machines. They have the ability to print continuous composites (our homegrown, weird, and very powerful 3D printing technology) which will let you print parts which are strength/stiffness competitive with Aluminum.
While our $69,000 printer definitely has an enterprise price-tag, it's still the cheapest (on an amortized cost basis) way of getting strong parts with a 24hr or less turnaround. The purpose of the laser scanner is to close the loop on what is typically an open-loop system in essentially all other 3D printers. I can't say too much more about this but we're adding a lot of cool features all the time.
(Obvious Disclaimer: I'm trying to sell you on the printers we make because I believe they are the best)