I had all of my own gear including two tanks before I did my checkouts. While it was nice having my own stuff and not having to worry about fit, function, quality, etc. It was also expensive as within two years I had to replace all of it. I did not spend enough time researching the different types of gear out there and chose it based on the shops recommendations rather than my future needs. In addition all of the stuff was not suitable for the type of diving I wanted to do. I was told it could be used for that but in truth that was just BS to avoid losing a sale. It was not until I found this board and got in with a couple of GUE trained divers that I discovered the gear I had was not suitable and could even be considered by some as dangerous for the types of dives I wanted to do.
As a result I sold all of it, have it sitting in bin or on a shelf, and try to advise my students to think carefully before buying and not to jump on the first thing that comes along. it's also why I think having them rent gear for a couple dives, IF THEY CAN GET DIFFERENT TYPES, is a good idea. I put OW students in jackets, back inflates, and BPW's during their pool sessions and let them decide what they want to use for check outs. The shop where I have them rent their gear has jackets and back inflates but not BPW's for rental. If they want to use a BPW I loan them one of mine or sell them one if they feel it is what they really want to dive in.
I have five and never take more than 4 students so it's easy enough to do.
There are positives and negatives to both owning and renting your gear as a new diver. You have to make a list of what the pro's and con's are for you. There is the initial expense yes but then you avoid rental fees and the chance of not getting a decent set of gear or even gear at all if the shop gets a run on students and rentals.
This is one of the things that a shop will use to get you to buy gear and it's a good one. But it's also what they will use to talk you into buying what's best for their bottom line and not necessarily your needs. As a new diver though you don't know that a $300 reg will breathe every bit as good as the $800 one they are trying to sell you on the types of dives you'll be doing.
Or that the lower end of the price range $250 BCD may actually be a better choice than the $750 one with all the bells and whistles and lots of d rings that are really quite useless to you is.
You can also buy used gear if you know the seller and know what you are looking for. Used fins are fine. Used BC's less than say 5 or even ten yrs old are fine as long as they hold air and you can get it checked out cheaply by someone who knows what they are doing.
Regs can be a crapshoot. Nothing wrong with used ones as long as it is understood that they may need a service that could add another 100-150 to the price. Shops will often sell off their rental gear every two years or so and you can get a good deal there. Just make sure they did the service on it before selling it.
There are also a few private sellers out there that for whatever reason take excellent care of their gear but have to have new toys every so often and as such will sell a recently serviced reg to get the new one that has an extra chrome strip or letter on it. You can get some good deals that way as well.
But before you buy your gear sit down and make a list of the things that now interest you about diving. Then every week see if it changes. If you know you DO NOT want to do wrecks and caves or anything tech and just warm water, a decent set of budget regs, travel friendly BC, and warm water regs will do you just fine for a very long time.
If you have any inkling of going into those other areas DO NOT waste money on jacket or back inflate BC's or unsealed regs. Start off with a BPW and a good set of sealed regs that are DIN or can be converted easily to it. Get regs that you do not need tools to take the second stage covers off of. And you don't need to buy $500 - $1000 regs to do that. Because chances are you're going to be buying a few more down the road to go on those doubles and stages.