We only stayed the 1 night on Moonstone beach but to be honest its such a great location that with your budget am sure you will get somewhere nice. As i said we got a deal because of the time of year and we were walk inns and i think we paid $119. (during our trip we paid between $119 and $400 for rooms to give you an idea)Am really fussy about hotels rooms but this really was fine in fact i liked it a lot,(except the breakfast) had a little fireplace which was lovely but don't think you will be needing it. Bathrooms are ok (but very clean) the rooms as huge and it was so nice to have the space and that wonderful view and sounds.
We also went to the early tour at Hearst Castle which started at 9.20am and moonstone beach is a perfect location if you want to do this the next day, just 10 minutes back up Hwy 1. (if you havent done Hearst Castle before it really is brilliant)
In Carmel we stayed at The Cypress Inn, Doris Day co-owns again we got a good deal (there are lots of dogs here!! but this wasn't a problem) the hotel is great really cute and in a very central location. Would have no problem staying here again and would reccomend it for its location. When we go back to Carmel am looking at maybe the Post ranch Inn or maybe Tradewinds they both look very nice but are more at the top end of our budget.
Hope the above helps sorry its gone on a bit .