Best deal on RMR's

As a proud new owner of a FNX Tac, I now have the bug to mount a red dot. Either going with RM02 or RM07. I realize you get what you pay for and buy once, cry once. But I would really like to pay less than $500 shipped if it all possible. Where are the best places to look and who traditionally has sales on RMR? This isn't something I need today so I don't mind waiting to get a good deal. Any advice is much appreciated. Or if you have any recommendations on alternate red dot sights for the Tac, I'm all ears.