I don't understand the question.
Are you asking if it is easier, safer, cheaper, available, some combination?
Cheapest would probably be 60m on air. You aren't using expensive Helium. You need the least amount of training. PPO2 is 1.47 (so quite risky) and narcosis is a limiting factor. The gear is standard twinset and stage so quite easy to achieve. If you are young and stupid, you can probably do it with a regular BCD.
If you already have the tec backplate/sidemount then the expensive route is to do it with Helium. This method has drawbacks like time and cost. Open Circuit (OC) scuba (air or trimix) is limited by gas supply.
Closed Circuit Rebreather (CCR) to 60m is much much more complicated. Currency is much more critical to sucess, compared to OC. You still have to be able to bail out to OC from the worst case. Some would say that you should be a Trimix OC diver before doing it on CCR. Even if cost is not an issue, the CCR still provides all the gas you need AND the gas is warmer compared to OC. I want a hot water line in the umbilical with Trimix unless it is very warm water.
CCR require different logistics. Sorb, O2 and Trimix blending at the surface. Some CCR are small enough to fit in carryon. CCR can surprisingly, be easier in remote locations and expedition settings. OC is easier in most places, especially if you learn independent doubles/sidemount.
My opinion turns on currency.
So if you dive a lot...CCR
If you dive "once in a while" OC
(Even if we leave cost out of the equation)
Break Even:
A twin 80 with Tx20/50 at $3-4/cuf is $240-$320 in Helium cost for one dive. Add $40-80 in deco gasses to get about $400 per dive. A CCR fully kitted plus training and enough experience to go to 60m is $12,000. So let's say 20-30 Trimix dives to 60m is break even. (Check my maths here)
Story time:
In the early 2000's "my friend" worked as an instructor in a popular vacation spot and picked up odd commercial diving jobs (Dcraping barnacles, raising drunken sunken boats, finding stuff that fell from ships at the port, retrieving expensive anchors, filming patch jobs for insurance, safety diver for welders...etc).
A mom and pop "party supply" store about an hour away was raided by police because it was a front for unlicensed "pharmaceutical supplies". While they barely did ANY business as a party supply store, they had baloon Helium regular delivery. This resulted in three large Helium tanks being stored nearby (in the same corral as the restaurants used for CO2 delivery). While the police were guarding the store and yellow police tape was all around the store, the tank storage was outside the perimeter. At about 9:30pm, a special delivery vehicle made away with three Helium tanks that mysteriously showed up empty a month later.
