50's and 60's... That's definitely drysuit conditions by a very wide margin.
Is a drysuit something that can also be rented at your local dive shops?
The computer - what makes you feel that it's a "real nice nicety?" What can you do with it that you can't do otherwise? What is easier about using one than not using one? Why do you believe this?
$150 gets you a lot of diving, my friend. Buying the computer doesn't get you ANY diving - it gets you a gadget. So if you're going to spend the money and you want to go diving, I'd say to spend it on diving - not a gadget.
Personally, I own several dive computers - contrary to popular belief, I am not "against" computers. However, in using many different ones and many different brands, I have come to realize that not only are they not necessary, but can actually be argumentative - disagreeing, sometimes with a very wide margin - with the plan, with tables, with other computers, with the software I used to create the plan - or what I know for sure to be the case. Deciding what to do at 80' where you're a little narked and under a lot of pressure and thinking about how much gas you've got left and where your boat is and where your buddy is and ooo... lookie the fishie... And where's the anhor line and how long have I been down here and why's my BC having an issue and what happened to the light I had and... You get the idea... Trying to decide at that moment whether you can believe your computer or not is really tough - and definitely not something I'd recommend, especially as a noob. And it's not like your life depends on it or anything... No, wait, it does.
Besides, buying a computer this early in your diving would serve only to teach you to dive on it's data... And that's a very dangerous practice, because they're often wrong - you've just got to hope that they're wrong conservatively, not liberally.
How deep are you diving? What kind of diving are you doing? Where will you be going? What do you plan to do there?
If you're a newly certified diver, then you won't be diving past 60 feet, right? If that's the case, then limit all of your dives to one hour, with a one hour surface interval between. You won't be able to get that much gas out of an AL80 anyway - your dive will be cut short because you're low on air.
...Which is to say that your computer won't do a thing for you. It's completely unnecessary. You'll run out of air or time or both. Why spend $150 (I wouldn't recommend a cheap computer, when you do buy one) when the only thing it's going to tell you is, "You're good?"
...But see, you don't know any of this yet. And if you dove with the computer, you'd never know it... That is, you'd never learn that.
If you were doing tables, by the 10th time you planned your dive with tables, you'd pretty much have memorized that you've got x minutes at y feet... And while your buddies were all arguing over who's computer said what about the dive, you'd know already how far from your limits you were.
...Then they'd start calling you "Scuba God" or some crap like that. And you'd look at them and say, "I'm not some kind of whiz-kid... Just look at your tables. It's easy."
This is akin to a 3rd grader, learning that 2+2=4, and trying to figure out what calculator he needs. He doesn't need a calculator. He needs to learn that 2+2=4. It's not like we're dividing by polynomials here - it's plain math, usually by single digits, sometimes by two.
...But I've said too much already. Steer clear of the calculator for simple math so that you can know what 6+4 equals. And steer clear of the dive computer so that you can learn this stuff while blowing your $150 on diving, not gadgets.
Once you've got 100 dives under your belt and your advanced classes done, then reconsider.
Other than that, it's mask, fins, and exposure protection for now. How impossible is it to obtain a good drysuit in your area?
Either way, I'm never diving with him again. Ever.
I dive wet down to 40 using a 7mm full suit and hooded vest. I actually find it quite comfortable. It's another one of those things that comes down to personnel comfort.
