The DMLS machine that is most common is an EOS270. The company that makes these machines has recently started adding some new materials. The new Material I'm most interested is Aluminum for chambers, and maybe Inconel 718 for a possible turbo pump.
I'd gotten some chamber quotes a year or so ago and it was still too expensive. When I had GPI quote my design again this year it was half of what last years quote was and I ordered the part on the spot. (In Stainless) GPI was also very helpful in making geometry suggestions that woul d improve the quality of the resultant part.
After placing this order I thought I'd do some more price research and sent the same file to Morris Tech to quote. The response from Morris was very competitive and its clear that this industry is seeing significant price declines. (Neither vendor knows what the other quoted) I hope its a sustainable trend and not a bloody battle to bankruptcy.
I really don't like beating vendors against each other because any long term relationship needs to be win-win and you can't do that by abusing your vendors. While it might be tempting to beat vendors prices against each other, its not some thing I do.
I also asked both Morris and GPI about the availability of Aluminum.
GPI indicated that they would soon be running Aluminum and Morris indicated that they had already run some Aluminum parts and that in the next few weeks they would be running some more aluminum test parts.
Since I was doing interesting stuff as an individual inventor not a big corporation Morris offered me the chance to add a single part to the Aluminum test run for approximately their direct cost. Its an offer I can't refuse. So I will soon have small DMLS chambers in two materials!
The Aluminum Motor is actually a bit bigger than the stainless motor as it needs to be cooled the whole length with a stainless cat pack support thermally isolated from the cooled aluminum chamber as a sleeve inside.
So if you need DMLS parts there are at least two really awesome DMLS vendors in the U.S.