Salisbury (North Carolina)
I'll be staying in Napa, San Fran and Santa Barbara for 2 nights a piece driving down the PCH. All other stops will only be 1 night each. In Napa Valley, I know I'm looking to stay NEAR Yountville in wine country, but the options seem slightly out of price range. Ideally I'd love $100-150 per night. Location is my biggest factor. Of course comfort is important for quality sleep, but other than that I don't plan on spending much (if any) spare time in the digs!
Napa Valley Railway Inn in Yountville is an awesome location and walking distance to the best restaurants. Website doesn't look like much: http://www.napavalleyrailwayinn.com/, but it is pretty cute. Each room is made inside an old railway car and there are rocking chairs in front of each with strung lights at night. A nice place to sit and enjoy that bottle of wine you just bought!
For your nights in Napa look into staying at El Bonita Motel in charming St. Helena, just 10 mins north of Yountville.
Check out airbnb https://www.airbnb.com/s/Napa-Valley--CA?price_max=150 I did a quick search and found a few places within your range.
consider airbnb in all of those places.
For SF, consider AirBNB over a hotel. There is a lot of supply, with great locations.