I was just at Menard's yesterday, and the prices of incandescent bulbs have just got obscene. 75W and 100W by Home Luminaire are nowhere to be found either. I think it's because they are trying to discourage bulb hoarders. You would think they would price them as low as possible so that they can be rid of them, and not throw them out to the dump when they don't sell.
Buyer's Choice 100W 4-packs: $9.99 (up from $1.29)
Sylvania 4-packs: $4.99 (up from $0.99)
Incognito Sylvania 75W 4-packs: $8.99 (up from $1.49)
Home Luminaire 12-packs: $11.99 (up from $2.97)
Sounds like supply and demand at work here.
The less there is of something the more its worth.