Sorry, what? The linked four pack of CFLs costs $6.97. You must have been doing some very interesting taxes this week if you think 6.97 / 4 = 0.74. (Apologies if you are not American.)
> Check the efficiency of [800 lumen] LEDs that cost no more than $5
They don't exist. Even cheap direct-from-China LED bulbs* are more expensive than that. $10-$15 per bulb is the typical cost and you'll be hard pressed to find 800 lumen (60 watt equivalents) for any less. I'll gladly check their efficiency if you can show me where to get that many lumens for that price.
* Actual lumens. Many Chinese reseller sites will outright lie and you need to check the manufacture's website. Eg, http://dx.com/p/193927 says 1008 lumens while http://www.sencart.net/e27-24smd-5060-led-pure-white-lights-... says 700 lumens.