Sand Dollar is okay and varies as stated above depending on the unit. I would describe the grounds and the condos as being similar to what my college room mate and I rented during college. Clean, comfy, and well used. The grounds aren't anything special. Fairly stark and basic actually IMHO. You could probably find a nicer and cheaper place on the water if you searched.
If you are looking for a budget style trip then I would suggest the Black Durgon or maybe Golden Reef Inn.
If you want a nicer room and want to be on the water Den Laman is an affordable option. Bump up in price a bit and you get another nice/popular option with Buddy Resort. The rooms at Buddy aren't as nice as some places but they are more than adequate and the grounds, facility, dive lockers, tank situation, truck rental, are all very convenient and reliable.
The reality of Bonaire is that even the nicest places are probably three star places if you use that rating system. Most places in Bonaire are one star type places but that's the charm of Bonaire. Build a true five star resort in Bonaire and it will look a bit out of place IMHO and probably wouldn't do very well as most go to Bonaire to get wet and have fun in the water, not to be pampered.
A PADI five star resort rating doesn't really mean that the accommodations will be five stars as well.
Happy hunting!