That estimate sounds about right.
You're right about the snorkel - most people use it for class, and then never use it again. There are a few that actually do use it, but from what I've seen, most don't.
Mask: Masks are all about fit, fit, and more fit. Get the one that's as simple as possible - one-window and two-window masks are the simplest, and you want the one that fits as close to your face as possible, minimizing the air pocket held within (and therefore minimizing the painful pull "up" on the underside of your nose). Closer-fitting lenses (defined as "low profile" masks) also tend to be easier to clear, less prone to stresses that can cause leakage, and minimize the "magnification" effect that happens when you're underwater. Today's super-soft materials mean almost any mask will fit anyone - but if you try a bunch on, likely you'll find one that feels like it was made to fit your face. As a side note, black-skirted masks tend to last longer (they don't show "yellowing" over time) and prevent "ghosting" - seeing the image of your eyes reflected on the inside of the glass due to a clear skirt letting light into the sides. Combining a black skirt with a low profile mask improves peripheral vision better than a clear-skirted, high-volume mask, too. Avoid four-window and more masks, as they tend to create a "high profile" mask and refract images in a funny way (think of looking at the corner of an aquarium and seeing TWO fish where there's only one... One in each window).
Fins and dive booties: Buy them together. Fit can be very different with different combinations of fins and booties. Try them on together in the store.
For what it's worth, most marketing with regards to fins is outlandish (they all claim to be "faster" with "less effort" - if that were true, then by now they'd all go by themselves), and most fins on the market today are too soft for scuba diving. This creates a situation where the diver "overkicks" the fin, which folds up worthlessly. Seasoned divers usually seek stiff, short fins that create a lot of power without being so long that the diver can't estimate where the fin tips are. The fins that most seasoned divers are using include the ScubaPro Jet Fin, the IDI Turtle and Rocket fin, and more. These fins also have the advantage that there is no plastic on the fin, which does get chewed up and fades in the sun over time.
Fins, however, are a favorite sales gimmick in scuba shops, so likely you'll be shown a variety of split fins and soft "paddle" fins like the Mares Avanti Quattros, Scubapro's SeaWing, and Aqualung Slingshots. All of them have their sales gimmick, but those who have been diving for a long time tend to use solid rubber, stiff fins that can't be overkicked and work for all kinds of kicks - not just the "flutter" kick.
Beware of fins that stress speed underwater - speed underwater is more dictated by streamlining and simplicity in your rig than fin design. That is, you'll be faster and better able to resist current if you're totally horizontal in the water with a simple, tucked and "squared away" rig than if you were diving a large air cell with every dangly you could find in the dive shop and trimmed in a "heads up" attitude in the water with the "fastest" fins on your feet. Seasoned divers, however, will tell you that "speed" isn't the most important thing about fins when it comes to diving, anyway... Preciseness and control trump speed any day - another reason why short, stiff fins are favored by experienced divers.
Resist the purchase of new gear. While you're obviously going to need your own mask, fins, booties, and (ugh) snorkel, the rest of the gear can usually be easily rented, saving you hundreds, if not thousands of dollars - which is a lot of diving.
So unless you plan on doing any serious snorkeling, the cheapest simple snorkel will do you for class. After class, you'll likely do like many of us and leave it high and dry collecting dust while diving. I also quite agree with Jay on the fins. Those old stiff fins even outperform the fancy long soft "fast" ones IMO, especially if your diving any sort of real current.
