If you have at least 1/3 the wattage with a red-blue combo (1 blue per 6 red) you should get better results.

Cheapest per watt I have found tonight:

High Tech Garden Supply

Has 50 watts for $139 or $2.80 per watt

Expect to spend $3 to $6 per watt for LED lighting.

http://www.ledgrowlights.com/univers...nn%20study.PDF

The research suggests LED's are better, just make sure you have at least 1/3 or more LED wattage to be fair to the LED's and you should be fine.

My understanding is that the initial cost will be recouped in energy savings (assuming you aren't stealing electricity) withing a year to three years depending on usage and electricity costs in your area.