The materials have been costly, but the earlier machines were, too. Added to that, because items are produced one at a time the per unit cost tends to be higher than unit costs of a high-volume manufacturing process. And that's exactly why this technique is still limited mostly to specialty and race cars, not volume automotive manufacturing.
Direct Laser Sintering technologies as a means to help Unmanned Aerial Vehicles has definitely been on Design News' radar screen for a while and is a great application for this technology. We wrote about one of the first UAVs built with this method taking flight this summer--SULSA,the Southampton University Laser Sintered Aircraft, which was printed using the EOS EOSINT P730 nylon laser sintering machine.
Curious how expensive this process is. You mention aerospace, medical and dental, where high costs can presumably be absorbed. Given the durability and ease of assembly (by aggregating more subassemblies into one piece), DLS seems like it should have huge uptake in automotive, but I'm guessing at this point that it's just too expensive.
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