Bonaire diving is not difficult. The hardest part is the shore entries and exits. Walking around on wet rocks in the surf while wearing scuba gear can be tricky if you don't take your time.
The basic way to dive Bonaire is to load the dive gear in a 4 door pickup and drive to a site ( marked by a yellow stone beside the road ). You gear up and walk into the water. They do have boat dives and guided dives, but that is usually just wasting money. Most everyone shore dives. The great thing about this is you get to set your own schedule. Since it is unguided diving, some experience is necessary ( they check certifications and usually require a checkout dive before they sign you up for the tank rentals ). But the waters are calm and warm ( I dive in shorts and tshirts there ).
I like to do a real early morning dive as the sun is coming up ( like a reverse night dive ). You can often see eagle rays feeding on the shallow sandy bottom then. Then either another dive or off to breakfast. Two more dives in the afternoon and a night dive. It is pretty easy to do a lot of diving when all you have to do is grab some tanks and throw them in the truck.
The main problem with Bonaire is the price of airfare. It looks like it is running $800 - $1000. It looks like renting a house for 5-6 people could be as cheap as $700 for a week ( a real dive ) to about $1500 for a nicer place ( and of course much more for even nicer ). Having a kitchen lets you save money eating at the house and getting food from a grocery store. A guy I travel with has a timeshare at one of the big resorts, so I have always stayed at that resort. It is nice but costs ( about $700/person and that including diving expenses for a week).
A truck costs about $330 a week ( 5 people in the cab, 6 is a real squeeze ). And a week of scuba tanks is about $135.
I don't know how much a travel agent could save by packaging, but these are just some quick comparisons I came up with using the 'net.
If you want to see some diving pics from Bonaire, I have some posted here (
http://www.underwaterblues.com/Bonaire/Bonaire.html ). Great visibility and lots of colorful fish, but unfortunately no sharks.