As far as I can tell, Ridgid cordless tools is really Ryobi's premium line (as Lexus is Toyota's premium line).
I don't know if it is a temporary offer or not, but if you go to the Ridgid website and register your tools within 90 days of purchase, you get a lifetime warranty that includes batteries.
As someone who has gone through three to four generations of cordless tools, this is a huge deal - I take good care of my stuff and after ~6 years end up having to replace a perfectly good drill, reciprocating, or circular saw because it makes more sense to buy a new kit than to buy replacement batteries.
I started out buying high quality tools like Bosch, Makita, and Dewalt, but eventually settled for Hitachi and Ryobi after realizing that these tools only needed to last as long as their battery (I'm a homeowner, not a contractor).
Furthermore, through 1/24/18, if you buy this kit:
https://www.homedepot.com/p/RIDGID-18-Volt-Gen5X-Lithium-Ion-Cordless-Brushless-Hammer-Drill-and-Impact-Driver-Combo-Kit-with-2-4-0Ah-Batteries-R9205/206127587
you get you choice of one additional tool free (which includes the 6.5" circular saw, reciprocating saw, boom box, or spare batteries) as indicated just below the price in the link above.
Alternately, you can buy the $500 kit and get to choose two additional tools:
All in all this seems like a great way to go and I'm thinking about going all in with the $500 kit,
but hoping to have some discussion here before I commit!
Comments/thoughts?