Dont put 1000 watts in a tent. 600 is plenty.
an led for u shouldnt cost more than 600. 1600 is just outrageous.
$2.50 per watt isn't outrageous for a fixture using high-efficiency diodes. Whether the OP needs high-efficiency diodes is a different topic.
But, it's definitely outrageous to pay that much for unspecified diodes. This seems to be one of the most predatory aspects of the LED grow-light industry. There's quite a few selling Chinese epi-whatever fixtures with a custom decal, web pages PT Barnum would envy, marked up to the price of high-efficiency fixtures.
$1.00 per watt will buy a Chinese epi-whatever fixture. As above, the OP should investigate the strengths and weakness of those products and weigh against his specific needs. There are a lot of people who are disappointed by these lights. They require as much or more w/sq ft than he's currently doing with his HPS. The usual recommendation is to go with CMH instead of these fixtures if you're in a space tall enough for CMH.[1]
The first question the OP should ask is why he wants to convert to LED? If it's to reduce electricity or heat, he should be prepared to pay the up-front costs of what is a long-term investment. If it's just to be able to say "I did LED before LED was cool," he should re-think his priorities. Or, accept that he's merely making a lateral step with Chinese epi-whatever fixtures. (Maybe not even lateral, he may use more electricity and generate more heat just to get the same yield and bud quality.).
If he enjoys DIY, he should build his own COB. He can get superior efficiency that isn't available from commercial products yet.
Whatever he does: Stay away from those expensive fixtures that don't specify the diodes they use. Ask yourself: with all the self-aggrandizing on their web pages, wouldn't they mention that they use a decent diode? Considering their zealous marketing, the fact that they're silent on this point should be interpreted as them using the same epi-whatever chips as what you can buy for 1/3 the price (a more direct import from China).
[1] In a short space a Chinese epi-whatever fixture might be prudent, one with 3w chips mounted on white backboard for close proximity to the canopy, conserving vertical space. But, T5HO would be better than that (in terms of efficiency and heat). Cree LED "lightbulbs" would be even better than that, but not as plug-n-play as other two choices.