Fence replacement- lumber cost wow

I have one section I really need to do and just cant afford to do the entire fence with lumber costs. The sections posts are completely rotted out and pickets could be broken through with a swift roundhouse..

Anyways, whats the norm these days. My neighbor said they are planning to sell and wont pitch in smh.

I havent even gotten a quote yet but has anybody just replaced a few posts hoping maybe prices drop?

Thanks