I purchased Standard a few months ago. I am not clear what it will cost me to upgrade from standard to enterprise. And when I do, do I have 2 years from the purchase date until I have to upgrade again. Should I upgrade every 2 years to always have the latest B4A? Can you supply a link that explains how all this works?
As you know you can chose between Standard and Enterprise licenses, then you could also buy the Enterprise now and the Standard after the two years.
Anyway, I think that the answer to your question is yes.
I hope that Anywhere Software will (should) also add a further discount for those who are a regular customer (it does not seem fair to me the same price for those who buy the license for the first time, compared to those who do it for years).
As @mangojack already tols it is entirely your decision.
In my experience you should stay up to date as there are a lot of changes in Android in the last years. And B4A always get adapted to work with these new Androids.
I am user since 2013 and i always have updated for 2more years. I never regret doing it.