Affordable is a subjective term!
I struggle personally with how much to spend on certain pins as the "inventory" fluctuates. I consider holding off to see if they will remake older titles (Monster Bash). Buy an old one and shop it up? Buy a remake or NIB ? What happens if the node boards go bad down the line?
I am still learning, but frustration sets in quickly when trying to conduct business with the secondary market sellers.
I notice more and more often they want top value for their machine despite having not shopped or upgraded it.
As for NIB as you started the thread with, I think its a tough call.
We want the companies to succeed thereby keeping the hobby alive and future releases viable. But who knows how well the value of these pins will hold up?
Case in point, Wizard of Oz; Buy a new one with all the bugs worked out, or save money and buy a home use/routed machine.
It isn't good for anyone when the prices go up. So I will suggest it is quickly becoming unaffordable....