[PvK]

Yes, I am already making them upgradable for 2.1. I had tried before but the way I tried didn't work at the time, but since then I have found a way that is working.

They don't even need to have a higher cost, IIRC. The better/bigger ones would cost more though, of course. But as an academic point, even at the same cost, upgrades cost a bunch. So, there's no way I know of to avoid making this a trade-off between "time to best Version" and "time to immediate results"... which, depending on the numbers, may be realistic enough.

PvK