I borrowed a snorkel from a friend when I took my certification course. I don't know if that's an option, but I passed the class, returned the snorkel and didn't buy one for ~4 years. I was pretty broke when I took the class, so I bought only what I had to (Maui 4, USD Blades, wt belt, boots - used from friend ~$100, new O'neill wetsuit). Years later, I was able to buy the stuff I have now. The LDS instructor was constantly trying to sell me ~$1500 in regulators, etc. Nice stuff, but when you don't have the cash, you don't have the cash. I can recall everyone in the class had brand new gear with matching colored masks, fins, hoses (that colored wrap stuff), BCs... I was a mess of colors - pink and blue Beauchat BC, bright yellow fins; yellow, blue, and green wetsuit - You could see me coming...
Whatever you end up getting, make sure that it's something that won't take away from the diving. If you get cheap fins, cheap masks, poorly fitting/maintained equipment, you can spend a good amount of the time on an expensive vacation screwing around trying to get things working right. When it's effortless and you forget that your gear is on in the water, its a fantastic experience. When you can't get your fins to stay on and your mask keeps filling with water, it's a wholely different experience.
I'm a believer in working with an LDS (a good one) for your first set of gear. Find one where they will let you try gear in a pool so you can figure out what you like and don't like. LP and other on-lines retailers are certainly cheaper, but it's hard to determine fit on some items if you haven't owned anything before. I buy plenty from ScubaToys, LeisurePro, DiveInn, etc, but only because I know what fits and what I like. I also still support my local LDS.
Good luck.