For me, the cost of renting an entire set of gear for all the times i'm going diving isnt really as cost effectine as owning. Plus, renting gear has the inherent flaws of:
1) Getting the correct size.
2) Getting good condition items.
3) Getting things that match (the Frankenstein look just doesnt fit me - not that i'm a fashion bug either).
4) Was someones urinary tract releived in the rental suit I just chose.
5) Is the gear in good working order.
By purchasing my own gear (which I must say is a great initial out of pocket expense), to me has the following advantages:
1) I know exactly what it is I have at all times.
2) I can dive and get comfortable with only one set of diving gear.
3) I can tailor and add any extras I might like - and leave them.
4) I have it available at anytime, anywhere (no rentals on sunday).
5) It has some color coordination about it (not much though).
6) I can always pass it on, resale or trade in on somethng better.
7) I can hang it up and just look at it.
So for me, owning was a much better option than renting.
Mike.