Hey man, I dig this project and signed up on this site just to comment on it. For those prices you could nearly buy DMLS parts, FDM should be very reasonable, unless you want that great finish of SLA. If these fit on a Makerbot you should be able to find someone to make them for not much more than the plastic. If you are having trouble with shrinkage try using PLA, I have my printer running at near 0.2mm tolerences depending on the print direction. What size envelope do you need to print your largest piece?