A pack of 10 15w 6,5ooK , CFLs cost $12 , light sockets cost $3 a peace , power cordes = priceless cuz I saved them from my old DVD player and such that died on me. For me growing with CFLs is better cost wise , heat wise , I have a 45w CFL going about 12 hours a day when I'm awake and it isn't...