That 400+ sounds expensive... find a "local" to do the introductory stuff. I paid 175 for my class, about 4 years ago.
(Unless that was for both of you).
You could rent, but as you said, it is expensive. You don't need dive computers, but they let you dive longer. I don't use one, but I would.
You can get gear off craigslist, just be careful. If they don't have maintenance records -- don't buy it. (Dont even look at it, this is your life talking).
Good first stage + regulator, go with a standard octo for reserve air, no need to spend the money on an AIR2. Get a weight integrated BC, it is really worth the extra hundred bucks. You probably don't need wet suits, unless you get cold easy. I have done quite a few dives without and usually didn't wear one for recreational diving. if it was a rough entry or going spear fishing I did.
You should come over to my house one weekend we can talk about some of this stuff.
As far as experience I have about 50 dives, nitrox, advanced open water, rescue, and I have paid for a deep diving course but stopped last year lol.