I suggest you start with asking yourself what type of diving you will be doing. Then, based on that answer, buy the items in the following order (until you run out of money). Buy the best item for your needs/situation and don't worry about renting the rest.
Mask
Regulators, Sea Cure mouthpiece, computer
Fins
Wetsuit
BC
Safety Sausage, whistle, mirror
Dive Knife, Dive Light
Mask
Regulators, Sea Cure mouthpiece, computer
Fins
Wetsuit
BC
Safety Sausage, whistle, mirror
Dive Knife, Dive Light