It probably bears pointing out that the upgrade mechanism for Sublime Text and how it tells you there’s a new build available has been in place for approximately 10 years.
For example, if you were using a beta version of Sublime Text 3 with an older Sublime Text 2 license at the point where ST3 was officially released, the exact same thing would have happened to you.
However, at that point there was no public outcry so it’s perhaps understandable why SublimeHQ, in their excitement to finally get the new release out, didn’t realize it would be received so poorly.
An apology has already been made and work is currently underway to alter the update dialog appropriately, so steps are being taken.
I’m not an employee of SublimeHQ, but I would also like to point out that the cost for Sublime Text license in 2017 was $80 USD, so a price of $30 USD would reflect the price of an upgrade at the time, not a full license price.
$30 spread over 4 years comes out to a price of roughly $7 a year for using Sublime, and that price will continue to go down because your existing license will work with ST3 builds forever.
It’s up to each individual to gauge the value a tool brings to their workflow with overall costs; no one tool is the right fit for everyone.