$2 per LED? Did you really mean a $, not a ¢? Basic LEDs (from half-assed ebay sellers) should be around $2 for 100 - ex: http://www.ebay.com/itm/261540613243
I'm amazed if you burned out a blue LED while simply applying 5v to it through a 220 ohm resistor. That should give you probably around 10 mA (assuming ~3v voltage drop across the LED - blue LEDs generally seem to be pretty close to this) - most modern indicator LEDs are spec'ed for 20mA, if you can scare up a spec sheet at all.
@Thomas499 Within limits, you can get more efficiency by running LEDs at a lower current than they're spec'ed at - it's well known that LED efficiency decreases as current increases; this is speculated to be due to recombination of electrons and holes as the density of such charge carriers increases. This is why most high power LEDs consist of several LEDs connected in series or parallel. I don't know if you'll still reap efficiency benefits if you try to dim it to 1/100th of it's normal brightness. Also, be careful when comparing LED mcd ratings. mcd depends not only on brightness, but how widely or narrowly the light is focused (review definition of mcd, vs the lumen).