Yeah that's tricky. I suggest Occam's razor: environmental control is likely to be the most serious factor? Any $1k printer should be able to extrude filament at the right rate in the right place, and I don't know that ABS is particularly challenging to melt. The difficulty seems to be in fume management (extraction) and the parts not warping on the bed?
Or you pay a lot of money for a higher end printer and make use of a support contract where they can figure out where your parts are failing.
One other suggestion would be to contract the parts out to a company like Shapeways and see if people are actually able to reliably make them in low volume, then try to replicate. May be a dumb question, but presumably you've tried to print the same parts in PLA or a more forgiving material to confirm that they are "printable"?
Oh, to be clear I'm not having parts fail, I was more trying to figure out ways to increase strength, along the lines of this article. Your comment is good advice if someone has a part that's tricky to print, though, good to keep in mind.
Or you pay a lot of money for a higher end printer and make use of a support contract where they can figure out where your parts are failing.
One other suggestion would be to contract the parts out to a company like Shapeways and see if people are actually able to reliably make them in low volume, then try to replicate. May be a dumb question, but presumably you've tried to print the same parts in PLA or a more forgiving material to confirm that they are "printable"?