Would you ever buy an IP worth more than your PPOR?

Our PPOR is worth way more than any our IP's.

I guess is really depends how far down your PPOR road you are....and some people start out purchasing IP's with no PPOR at all.

As time goes by most people upgrade their PPOR a few times usually into something bigger, better and more expensive so that in itself would place their PPOR ahead of IP's.
It's all psychological. Work with the numbers. If your IP ends up being more expensive then your PPOR - but you're confident the numbers work and it makes for a good investment, then so be it.
^^^ this. The value of an IP compared to my PPoR is not a consideration when I am looking at purchasing an IP.