If you bought a product - you can buy modules at any time, paying only them. But if you have not paid support for half a year after purchase, then you need to buy again. HA This time the interface is very much changed - changes a lot appears. And maintain the old version, we are simply physically not able. That is why it will have to buy again. But at the same time the old version will work all the time. If you have not violated the terms of the agreement.
And you wanted to buy one and then pure everything you did not buy and get a complete assembly? Don't you think that this is meant?