My standard answers recently changed...
On one hand, it's still true that - for the cost of money that could be tied up in good Scuba equipment, the speed in which equipment can become outdated, and the likelihood that a Vacation diver would know his equipment well and keep it serviced - it just might not be economical and prudent to buy the more expensive pieces, like a BC-Device or Octo-Reg. Besides, if you rent your gear after you arrive at your destination, you won't have to pack and carry it, you won't be responsible for it en route, and if it malfunctions there - it's their problem. Or, would it still be your problem??
It'd only take one drowning to blow that approach apart. Even one trip to the chamber because of a malfunction, or one night in a hospital because of saltwater aspiration. With the rental gear I've seen people using, and the problems I've seen firsthand as well as read about here, my suggestions will be more like:
"If owning your own gear is not for you, Scuba just might not be either...?!?"
Rental gear is probably a lot safer obtained in the U.S. than outside - where U.S. rules and regs don't apply, and perhaps one can even find dependability renting from one's hometown LDS and taking the equipment with them? It'd be best and safest all the way around, though, if the diver would at least buy, own, and maintain his/her own:
(1) BC-Device;
(2) Octo-Reg with Safety Second;
(3) Safety Sausage; and
(4) Storm whistle.
Plus, if your BC is not weight integrated, and you'll use a web belt, at least own and take weight keepers.
A Newbie friend of mine recently told me that he was tired of fighting rental gear and was ready to own his own. I suggested that he might have to go at least 2 or 3 trips a year to make it worthwhile, and to keep up on his gear maintenance; he was good with that. But then, wouldn't you want a dive buddy to be at least that committed...?
don