Mineralz:
The lights are definitley more up front. For example some killer ones would be the Penetrator 126W Pro or the 357 Magnum ($635 / $750). But here is the thing. A good 400 - 600W HPS with a remote ballast will set you back about $300.00. That's just for the light, hood and ballast. Now you have to also consider "cooling". You need insulated ducting and a good fan. Not a cheap inline fan, but a centrifugal fan. The fan and ducting will be $200 + all day long. Now last but not least you have electricity and bulb changes. Ideally you want to change the bulbs every two grows. After that your yields will start to diminish. Bulbs are $25.00 or more depending on what brand you get. A good Hortilux, Digilux can run up to $100 depending. Yeah thats a lot, but who wouldn't want the best for their plants? If you do 4 grows a year (one every 3 months) with a 600W HPS and change bulbs twice a year, you're looking at $60 - $200 depending on what brand bulb you get. Add the extra electricity (let's say a conservative $15.00 extra a month over an LED) you're looking at $180.00 annually. Of course with the cooling fan running (during lights on) you have more noise. In my case no problem. But if you're in an apartment, or rent part of a multi-family home noise may pose a threat. And chances are you have to have at least "1" fan being used for exhaust.
So here's a breakdown for one year with a 400 - 600W HPS (And these are very realistic for good equipment, not Chinese knock off crap):
- Light / Ballast / Hood (Good quality Brand) $300.00
- Centrifigal Fan $150.00 (And remember for each light you need a fan and ducting! So multiply extra electricity and up front costs)
- Insulated Ducting $ 25.00
- Electricity (Extra over LED @ $15 / mo) $180.00 (Annual)
- (2) Bulb changes @ $35 a bulb $ 70.00 (Annual)
So for one year with an HPS setup you're at about $725.00.
A Penetrator Pro 126W costs $635.00 and a 357 Magnum costs $750.00 (inc no tax and free shipping) from the manufacturer.
And to top it off the "quality" of the bud seems to be better from the grow journals I've read, and people I've spoken to who use them.
Anyhow absolutely no "attitude" intended here Mineralz! Rather I'd like to thank you for bringing up the "cost" factor. Because for most of us (including myself at one point) the initial cost of a good LED is a show stopper.
I like your math, but think you made a poor choice for your LED comparison as that penetration pro wants over $5 per watt when everyone else is charging less than $3 per watt and sell more technologically advanced panels (blackstar 3w is like $2 per watt and GLH 3w is just under $3).