I’m not in either industry either, most of what I’m saying is based on what I’ve gathered as a space enthusiast.
The cost issue is multifaceted.
Most of it is sunk into launching itself, which is where things like space tourism come into the picture as a way to provide an initial business case and eventually, economy of scale. Addressing that alone will improve the economics of off-world industry quite a lot just on its own.
For the other part, initially companies will just have to eat the cost to get things up and running. This really isn’t that unusual — we just haven’t had much in the way of truly new frontiers in many years and have grown accustom to business ventures being relatively low cost and low risk. That said, this could also be partially subsidized by researchers and tourists, since there is certain to be interest from universities and other organizations to send people to study these other bodies, and there are most certainly a surprising number of individuals both wealthy and crazy enough to want to go stay on Mars for a couple of years.