Helo chopficaro,
The problem is, these two things don't exist together yet. You can get cheap LED's, or powerful ones, but not both in the same light. The technology hasn't gotten there for that yet. There's a lot more to a LED light than just the wattage it uses. Good LED's aren't cheap. Cheap ones can still grow plants but don't have the same output and throw as the good ones do. So bottom line you need more cheap ones to do the same thing as a good ones. If you need to buy multiple cheap ones, that isn't any cheaper than buying an expensive good one to begin with.
While LED's are a good technology to grow plants with, the industry/manufacture claims that their cheaper than other lighting options because LED's use less electricity is minimal at best (so far). And the high cost for LED's make the LED option the most expensive option. I'm not saying don't bother with LED's, just be aware of their capabilities and limitations. Don't trust the manufactures and retailers propaganda, do your own due diligence before spending the money. That is unless you have spare money you don't mind experimenting with.
As an example: the LED light you posted has very little information. Including NO information about the manufacture other than it's in china. That in itself is a huge red flag for me because I can't check out the company and/or their product quality. Also they advertise it as a 1,200 watt LED, but if you scroll down it says "Real Watts: 340-380w", It's not a 1,200 watt LED (borderline false advertising), it's a 340 watt LED. You would need 4 of them to reach 1,200 watts. At $193 ea, that would cost almost $800 for 1,200 watts.
Typically with good LED's each individual LED bulb will use one watt per bulb. So if it has 300
bulbs it will be 300 watts. If it's a 1,200 watt light it should have 1,200 LED bulbs. But like I said good LED's aren't just about how much wattage they use, it's also about the electronic circuit boards behind the bulbs. The electronics are just as important as the type of bulbs they use.
Just my 2 cents...