I think this is more about what each of us wants to spend money on, versus waste money on....
I think an expensive computer is a complete waste of money....I can dive any recreational dive site anyone on this board can dive, and do it with a depth gauge and timer, and do as much or more bottom time per day as they will in a 5 dive per day trip. Alternatively I might go with a relatively inexpensive computer like the cressi edy I bought for freediving( and is also a Nitrox computer), but if I was challenged as to how much I could spend on gear, it sure as heck would not get wasted on a computer.
Likewise, I could dive a $200 reg, ANY place you could dive a $800 reg.....and there is a good chance my $200 choice would be more reliable ( say like the old Mark2 SP reg I have from the early 90's, with the R190 2nd stage...it NEVER, Ever breaks, and I have dived it to 300 feet deep). The high end SP reg I normally use now breathes a little nicer, but really, the price difference is a waste---all you need is the cheaper one.
I don't even need a BC for diving in the tropics..it's a huge waste of money....With a suit with no buoyancy swing, why the heck would you even want a BC on your back? With an Al 80, you can be just the tiniest bit positive at your safety stop...no big deal....So why waste upwards of $400 to $700 or more on a BC? Just get the lowest drag, cheapest and most minimal BC you can get, unless you have lots of money to burn...
Fins are what actually get you around....Fins are what can actually allow you to save your own life. Fins and a decent mask and snorkel, allow you to handle ANYTHING the ocean can throw at you....What I am saying is, if you have $1000 or $2000 to spend for dive gear, you buy the best fins for you first....NO OTHER piece of gear matters as much...Once you have your perfect fins, get a good mask, and then see how much money you have for a reg...then what's left for a BC and exposure suit ( ** I am still talking about the tropics--I choose not to wade in to the issues involved in cold water diving
There are some massive differences between fins...Some really terrible fins, that could make some dive sites downright life threatening, while a different pair of fins could make the same exact dive site lots of fun, and easy.
You really need to demo a lot of fins, and in a perfect world, there would be someone helping you with this, because some fins require specific kick shapes and coordinations, that are not intuitive. This would be the "right" instructor, from the right shop