It’s very difficult for a new diver to know what type of gear might suit them best.
This is why buying used can be very challenging, they do not have the personal knowledge yet and experience to know.
Sites like this help for sure, but there is also a danger of overwhelm and the newbie getting their head spun around throwing them into a lot of confusion with dozens of opinions.
If they go through their LDS then they risk being oversold on everything, as
@boulderjohn stated, they are more interested in profits than the best interest of the diver and their budget.
Looking back at my first purchase, I could probably been happy with a basic MK2 and a couple of R195’s instead of a MK20 and an Air2
The Air2 was all the rage then and all the divemasters used them. I thought this must be the best it gets so I got one, not knowing that the shop made them wear all the stuff they wanted new divers to buy.
The shop did carry lower end brands like Oceanic but they steered me towards Scubapro. I did ask about the MK2 and they said it was only for warm vacation divers diving in benign conditions and it wouldn’t work up on our coast. Besides, the MK2 wouldn’t provide enough flow to operate the Air2 (which I know now all of this is utter BS!).
When I looked at BC’s, I could have been fine in a lower end jacket not knowing then that I would be changed out in a year. They sold me on the most expensive tech wanabee BC because I was a big guy and big guys needed a bigger better BC than others (flatter flatter). Besides, cheaper BC’s wouldn’t work up on our coast because they didn’t have enough lift and were not heavy duty enough (another line of complete bull crap!) I could have easily used a regular mid range jacket no problem. The salesman purposely stood in front of the cheaper jackets to block the view and faced the expensive BC to present it with a clear visual shot.
So the point is, you have to be really careful who you listen to.
I can’t recommend enough doing a lot of local dives first with rental or borrowed gear with some local mentors (if you’re lucky enough to have both available).
That would even get you enough experience to possibly know what type of gear to look for used.
A good rule of thumb is: The gear doesn’t make the diver, the diver gets good enough to make use of any gear.