Without doing something like joining Cardrunners or signing up to one of their affiliate poker sites, you're not going to find any cut-rate deals on HM2 or PT4, outside of the occasional sales they offer.
HM2/PT4 are incredible values considering their value and ROI, so you should just save a few bucks and buy them. They'll pay for themselves in no time if you apply them properly and learn from them.
We have upgrade discounts if you own HM1. We also have the Get-It-Free program linked above. We do not have any other promotions currently.
Yes, this is legitimate. You will have to be a logged in member of their site to get it.