and after I watched some being disinfected I swore off using anything but my own from then on. Of course then we got certified in scuba so that helped but I would think if you plan on using it a couple of times on this next trip you are going on it would be worth it.
The masks usually always leaked on us when we rented and it was miserable. Also the snorkels didnt always have the purge valve on them so if you got some water in your snorkel which you are bound to do at least once it would go into your mouth instead of out the bottom of the snorkel.
If I were you I would look for a couple of things when considering equipment.
#1 Mask fit is probably one of the most important factors. To see if the mask fits your face properly take the mask and put it on your face without the strap on....just push the strap up and then breathe in with your nose and hold your breath for a second. If the mask will stay on while holding your breath without any hands and if you cant hear or feel any air escaping it will be a good fitting mask.
#2 The snorkel as I said before you would be wise to make sure it has a purge valve in the bottom of the snorkel below the mouthpiece. It would look like a little strainer almost. I would caution you against buying one unless it has that valve. Here is a link with a picture of a snorkel with a purge valve
http://www.divebooty.com/equipment_details.asp?pid=2683
you can see at the bottom of the long straight tube is a blue colored thing...that is the purge valve just below the mouthpiece. Also if it has a mask clip even better. It will clip onto your mask and you wont have to clench your jaw to keep it up out of the water.
Also if you do end up buying a mask when you first get it home take some toothpaste and wet the inside of the mask with water. Then scrub the inside of the lens with your finger and toothpaste to get off the film. If the film is still on the mask it will be almost impossible to get it unfogged when it fogs up. Also if your mask does fog up the easiest and cheapest thing to do is to spit in the inside of your mask and spread the spit all over the inside of the mask and then rinse out with ocean water or whatever water you have and then put it back on. There are commercial defoggers that work well and are only 8-15 dollars usually but if you dont want to buy one of those spit will work almost as well.
HTH
Heidi