Quoted from JY64:
I don't care whose problem it is I will take exception with anyone who thinks buying a $10,000 game that you need a back-up playfield is a good idea. Advising a fellow pinhead to do a full playfield swap when you do not even know if he can build the rotisserie needed to do the work is even a worse idea
Having a spare playfield means when and if you want to do a swap, you won't be stymied by availability. As for who will be doing the swap, owner or an experienced shop like HEP (dreaming outloud) that is a different topic altogether.
Lastly, whether or not it is acceptable for a NIB machine to have a damaged/defective playfield, I vote this is not ok. Clear issues should not still be plaguing this industry.