season pass is a way how to support CDPR for their work on expansions. You can buy it now, and will get the expansions later (first one in october, second one next year)
Is there even any saving to be made buying the season pass or do CDPR simply need some funding pre release? I only ever buy season passes if 1) they offer a discount i.e. 2 for 1 etc and 2) when they go on sale. I have never seen a single season pass that hasn't been on sale before all dlc has been released, so I wouldn't ever buy one at full price when the dlc in question is going to be staggered.
I bought it to support CDPR. Game alone is worth more then 60$. Personally my brother deals with TF2 and CS items full time. I didnt have to pay anything.