Quoted from chuckwurt:so shipping does come into play here. Comet's order was 29.5% cheaper than Pinballbulbs, and 22.8% cheaper than CT. Just food for thought for the OP since the CT discount has seemed to go away, and they just offer cheaper prices.
Shipping time does come into play also...Comet for me tends to take much longer than CT. Comet bulbs "seem cheaper" to me looking at them, but you're not going to be looking at them most places you put them.