I’ve stayed in Sayulita and I can’t suggest it enough.
It’s inexpensive, really accessible, a reasonable drive from Puerto Vallarta (you can take a cheap bus there) and has a lot of amenities – especially if you don’t want to rough it entirely. It’s not as built up as many of the other Mexican tourist spots like Cancun, Ixtapa, etc. and still retains some of the small fishing village/surfing village charm that it started to get attention for in the 60’s and 70’s. A lot of people in the small town square speak english and it’s easy to get a local Mexican experience, mixed with some of the comforts from home, if you need them.
They do have really inexpensive bungalows and palapas right by the beach – as well as great deals on breezy houses, within a 5 minute walk of the town center area. Also, if you feel like doing some low-key, girly spa stuff on one of those days, you can do that too. Check out this link for more info.