I'm sure you think you do, but you probably shouldn't mislead others by advertising it as a "legitimate" product.
There is nothing legal or legitimate about reselling TechNet keys.
The keys are perfectly legitimate. They are straight from Microsoft, and aren't torrented, or fake generated keys.
That's not what I said, is it? The keys are valid (for now). Your operation however is illegitimate and what you're doing is illegal.
People buying from you might as well torrent the products and save themselves a few BTC. Either way, they will have no valid license to use the products.
When Microsoft terminates your account and blacklists all of those keys, your "customers" will be left on the hook.