You are exaggerating or overhyping the savings. Since you are saving slightly over $1 per day, and ten bulbs cost almost $2.50, payback is really slightly over TWO days.
The well-aged CFL, pics attached, new CFL included for reference. But you know, a scientific attitude is a burden, when it comes to these things. It would be so nice to be proud to own such a long-lived light bulb, when others are cursing the short lives of CFLs. But me, I have to measure the light output. (Doesn't everybody own a light meter?) Same lamp, same distance from the light meter, measuring draw with a Kill-a-Watt: Methusala bulb: 12 watts, 254 lux. Brand-new bulb: 13 watts, 852 lux. Conclusion: What a dummy. My well-aged CFL is scarcely better than a last-century incandescent. I have now retired it in favor of a new 9W CFL, current knocking out 390 lux under roughly the same test conditions. So, extreme short life for a CFL is a bad thing. But extreme long life for a CFL is, maybe, not such a good thing.
I did until I dropped my flux capacitor on it. What is unhelpful, is the number of various bulb packages that don't include the lumen rating.
Lumins are really the most important rating of the bulb, it's usually in small print if at all on the label. People are used to thinking watts, not light output! The first generation bulbs are all the low output varity. They were nice way back when, but now, I would think the much brighter 2nd gen are nicer. As time goes by, things are getting brighter, better, cheaper, and draw less wattage. However, at what point do you want to jump into the game and replace all your lights with better CFL's or LED's. No matter what you buy, in about 2 years, the next generation of both will make what you just bought look like energy hogs! If your looking for a lifetime payback reason, I think your wasting your time. if device production technology maintains a linear rate of improvement, you might have a chance to make those numbers actually come out even! But progress in electronics can be more of a logarithmic growth, and as a result that throws a big wrench into the payback calcs. I think at this time LED's are way overpriced, and are just not bright enough, just like CFL'S were 10 years ago, A good efficient CFL with a high lumin output would be a much better way to go, compared to a LED that cost's 3/4/5 times a much for a comprable Lumin output! I would think in say 2 years from this date you will be amazed at what there is available, and the pricedrop should be considerable. Two years after that??? Who knows! I replaced some of my CFL's on this agenda, BETTER is BETTER....upgrade, or fool yourself your doing good and sit in the dark! Entropy, it's a bitch!
Considering that he was sweeping out existing, functioning, paid-for incandescent bulbs, they must be assigned a cost of zero.