Where to get Carbide Drill Bits for PCB drilling that fit a Dremel?

[Evad Nomenclature]

Yeah...
as the subject says...

Anyone know where to get carbide drill bits for PCB drilling that fit a Dremel?

I bought a half dozen or so of the ones from small bear (the steel ones) But I notice that after I finish just a couple boards, they start to get really dull and don't fly through the board as easy.
I saw a couple other threads where people say that they "get old and dull" after around 100 holes or so which seems about right.
So!  I want to try those carbide ones.  Haven't had any luck finding em anywhere.  SOme on ebay , but they are in sets of 50 and all preused or something.

Any ideas?
thanks
dave

[rnfr]

drill bit city.  you can get resharpened ones for cheap.

http://www.drillbitcity.com/

[The Iron Chef]

Manhattan Supply
http://www1.mscdirect.com/Circuit-Board-&-Micro-Drills/Drills/Cutting-Tools/s605.HTML