I was quite frank with them about the maintenance price of my permanent licence, which was that it was unaffordable. Plus the new policy that if you don't keep the maintenance up and want back in, you must buy another full-price licence. I was officially told that at the time of my renewal. They offered a small discount presented as a "great deal".
In the end I offered them a "this is what I can afford, take it or leave it" counter offer just on the renewal date. This was true at the time, as customers hadn't paid up so cash was tight. I was happy to let it lapse if they didn't accept, but they did. So it cost comfortably under 50% of what they offered. If was accept that or nothing.
Being a small company helped I think. I've quite a lot of time invested into Altium now, and got a permanent licence at a huge discount following various offers and schemes a few years ago. So I wouldn't want to migrate away unless I really have to.