These are pricey when purchased new - I've only bought two of them new in the entire time I've been using them. The replacement needles are available commercially, and to my knowledge are NOT under any sort of biomed restrictions. My wife says there are many biotech-type resellers online who sell these things at a significant discount.
Hank - the syringe you saw in my photo is a model 1705. I've had it for YEARS and the only trouble it has ever given me is that - after prolonged periods of non-use, I sometimes have to draw liquid cement in two or three times so it will get a good seal again. Takes about 5-seconds.
The needles I use seem to me to be heavy gauge - if someone tried to stick me with one I'd probably pass out. They are 0.70mm OD. I file them to an angle that I need. That way I can use the plunger to develop a tiny "bubble" of cement at the tip, then rotate the needle around until the cement wicks into the part being assembled. For long seams I use a needle with an almost perpendicular cut, then draw the needle down the seam while applying the desired amount of pressure to the plunger. Not rocket science, but certainly takes a little getting-used-to.
Here's most of my stash which I've accumulated over the last 10-15 years. They range in size from 25 to 1000uL. Most of them are from Hamilton, and I have a couple of monsters (500+ uL) from GlenCo - take a look at p/n 19925 for example). The plastic cases are replacement needles - you should be able to get an example p/n from them. If I get a call from the DEA I'll know who to find...