I appreciate knowing the deals people find at HB so I thought I would share my most recent experience which ended about 5 minutes ago.
I bought 3 packages of 300 W Halogen bulbs (2-packs) for $1.00 per package (warning?).
2 of the bulbs glowed "dim" out of the package, and 2 of the bulbs made an annoying vibrating noise (I replaced the 2nd one faster than the first, after I determined where the noise was coming from--determining this was not trivial due to the nature of the lamps--it's not like you can look at them when they are turned on!). The other 2 bulbs worked just fine.I just replaced one of the noisy bulbs with an "expensive" $2 bulb, and it works just great. Even at "1/4th the price" the savings is not worth the trouble unless you are indifferent to the level of brightness or the vibrating noise. Since I use the lamps in my home, for me, these factors weren't negotiable.
Well, you have been warned :)
Bill