My dude, hear the words of wisdom and you shall be handsomely rewarded if you heed them.
You are not Adobe or Autodesk to pull off a subscription model. Not successfully.
Sell a perpetual license that is valid for the current version plus anything that is released in X months after that.
Then, sell an option to extend the access to upgrades for Y% of the original purchase price once X months are almost over. If X months are over, sell the same option with a mark-up.
This is universally perceived as a fair arrangement and it gives you a recurrent revenue from people who do keep on using your software (just like with the subscription). Best of both worlds.
You are not Adobe or Autodesk to pull off a subscription model. Not successfully.
Sell a perpetual license that is valid for the current version plus anything that is released in X months after that.
Then, sell an option to extend the access to upgrades for Y% of the original purchase price once X months are almost over. If X months are over, sell the same option with a mark-up.
This is universally perceived as a fair arrangement and it gives you a recurrent revenue from people who do keep on using your software (just like with the subscription). Best of both worlds.