All other building products are going up only a matter of time. Glass companies have all raised or are announcing price increases. Only going to get worse with the alleged repeal of the corporate tax breaks.

The prices of all building materials regardless of manufacturer have and will continue to go up due to high demand and low supply.... Other issues like MWM mentioned will only amplify that. In short, Pella in particular may or may not be going up precisely on Dec 1, but its likely that they will or already have. In many cases dealers absorb price increases from manufacturers for a short while until they institute them in their own pricing structure. That could be a possibility as well.

All building materials are going up and quite substantially. The window industry is expecting more increases in 2021.

You can't find anyone that will honor a quote more than 30 days old because the market is so viotile right now.

You dont want Pella windows anyways.

Just built a "Tree House" for the grandkids. Budgeted $1k, spent double that. Ended up using Trex for the decking because it was the same price as pressure treated 5/4" boards (I'm not kidding). A 5/4"x6"x12' was over $20 in SW Florida. Trex Board was $21.