2 250w would put out 22,100 lumens of GOOD light, household CFL's are not made for growing, and if you place your lights right you'll cover it. Thats why you every time you see a household CFL grow the buds are like half gram buds, i dunno about you guys but 10 grams a plant is a fuckin waste of time.
first 250w cfl's are expensive for some folks.
The only reason you end up with 1 gram buds is because there is no one spot above the plant that is bright enough to make the plant healthy, combined with the often times no air movement of small grows being educated is much better then making assumptions. A light spectrum is the same from 14w - 240w wattage makes no difference on the spectrum only how far into the leaves the light penetrates. Using 23w cfl's in a broad spectrum style will lead to better buds(quality) if done right, how ever with a huge amount of poorly educated people out there (through no fault of their own) we end up with the main top light source being spread out and weak. Such to the 1 gram pop corn buds every where.
A simple and effective way to handle this problem is to get a 5 gallon bucket( something larger in diameter works better) cut holes around the bottom approximately 3 inches up every 4 -5 inches large enough for the screw part of the light to fit through then attach your socket to the screw part on the out side of the bucket thus holding the light horizontally in a halo fashion then (with out light installed) cut the rest of the bucket off 5 inches above the light holes this is the most cost effective grow light you can make using the spectrums according to the plant phase you will produce larger buds. Using a phase specific spot light in the center of the halo in a hole large enough for the ballast to sit out side the bucket will greatly increase the effective light foot print. for extra sugar make sure to always have a few lights that have out of phase spectrum. example would be in flower, have 2 6500k bulbs along side the 2700k (2100k if you can find them cheap)
Dropping lights down the side of the plant is a key feature in making use of you're 4 pack of each spectrum. I have had great success with 4100k in the most current grow, i would suggest 1 4 pack of 2700k 4100k and 6500k totalling around 35 bucks. Where as one 250 watt can cost 60.
Through experiences we gain knowledge, through application of knowledge comes intelligence.