I am in the same boat. I’m new around here and want to buy into the whole suite of products.
Devonthink, Devonthink To Go, Devon Agent
Since these are versioned it is a shame for me to buy the old versions of To Go and Agent so late into the product cycle.
I wish there was a subscription model like Omnifocus has that you pay every year and get access to everything available at whatever current version.