We found the Family Inn, a very clean and Friendly Family Run Hotel. It is on the outskirts of Argassi, but will only take you a 5 minute walk into the centre, but you pass lots of lovely Restaurants on the way. Once you have stayed at the Hotel, if you ever go back you will not be forgotton (especially by Dino who runs the bar) Highly recommended.
Prices depend on what time of the year you go. You will have to book through a Travel Brochure, as the Family Inn's rooms are bought out, you cannot just ring and book that way. I think when we booked we went with Airtours. Hope this is of some help.
Locations visited were great, but beware if you have small children or you suffer with acute sea sickness (take it from one that knows) it can be an extremely long day, the trip we took lasted 8 hours. Take your own food and water as there is not much available on some of the boats.
We stayed at the Commodore last Summer, most of the Entertainment is at the Admiral's(just across the road from the Commodore)the only thing that we found was there is quite an incline to get to the commodore, so if your parents are elderly they may have problems, but as long as they take it easy they should be ok. There are quite a number of steps to get into the main building, but the one big advantage is because it is high up the views are terrific. The Captains do meals which are a buffet style, you pay one price and you can eat as much as you can, and again the view is brilliant. The rooms are very basic (but aren't they all) pool facilities are not brilliant, but clean. Hope this is of some help.