I haven't paid a dime for any updates with OS4. I can decommission any Windows license easily between hardware, locking out the previous hardware. I am not trying to be a dickhead, I want answers. One guy from the MOS camp said "it may be possible if you can prove your mac died in a fire", the others say "no", or simply won't respond. I'm not trying to screw anyone, I want to pay for a product I like!
Weren't 4.0, 4.1 and isn't 4.2 paid updates? And can you transfer your OS4 bought for AmigaOne for Pegasos2 use for example?
And what would be a good way to lock out the previous hardware? Any need for online interaction when installing is absolutely no-no. With this kind of small business you can't trust there will be services available "forever". Blacklisting machines in next updates won't stop machine being used with current and earlier versions and might need too much work to kept updated... but I guess that would be only reasonable option...
Anyway, if your previous machine breaks down, it's known that keyfile can be transferred to next machine.
Again, the problem being is I have a nice Mac Mini sitting here I would love to register MOS on for the interim, but I know I will end up wanting MOS regged on a more powerful system not long after.
If it has 64M vmem and you're not interested about PowerBooks, I'd say go for it, register and enjoy

Or get the PowerMac G4 you know will be powerful enough and register for it. But if you're waiting some other new powerful system like G5 macs, it's not going to happen in that "not long after" time for sure. You know your options for next couple of years and I think it should be enough to make a decision to reg the system you like now.