Here's the problem with the rent versus buy argument....
I've lugged my equipment literally around the world. It seems like everytime I go, I wind up fixing, buying, borrowing, or hacking together my setup. And, I've got really good equipment. But I still have the risk of failure because I'm not experienced enough (50 divers) to REALLY know how to maintain my own equipment.
If you are a new diver and can't trust your dive shop to maintain their own equipment, you are diving with the wrong group. You had better learn right here and now that this is a dangerous sport. A bad divemaster can kill you more easily that bad equipment can kill you.
Don't get on this forum asking about which equipment to buy. Get on this forum and ask who you should be diving with. A good dive shop will not take risks with poor conditions, poor guides, or poor equipment.
For your first couple dives, rent the equipment from your local shop. They can check it all out before you go. You can take it to a local pool and learn how it works. And, you can even buy a brand new mouthpiece (with no cooties) for an extra $5 bucks. If you like the equipment, then you can always buy it from that dive shop. You are better off renting well-maintained equipment from a reputable shop than buying new junk off the internet.