While I don't think it is at all necessary to lower the cost of entering the ruins, I did struggle a bit coming up with the initial gold until I realized I should just sell one of my extra stacks of 99 stone from my many days of resource node farming. Perhaps your first time in the mines, or perhaps one day per week, the maintenance fee is halved?
Alternatively, having some easier early-game commissions that don't require copper, such as stone stools/tables, that could easily be made with a single day's worth of resource gathering, that gives 10-30g rewards, at least for the first ingame month; that way, a new player could easily earn that initial 80g in a few days, possibly even get into the mine by the end of their first wee if they're lucky. It definitely shouldn't be TOO easy though; I like the fact that you have to put in effort to earn your way into the mine, and it makes you think carefully about whether you can take best advantage of going into the mine that day. On that note, we absolutely need a way to cancel accepted commissions - if that's already a feature in place, I've failed to find it thusfar.
I love the idea of local competition suggested above, too. You do have a competitor living in town with you - your top competitor, even, and Higgins has been shown to cheat the system when he can, ruthless as he is. However, it might be tricky to implement. Perhaps if there was the ability to open an actual in-town shop that you stocked with items, and Higgins (and maybe other characters) did the same, with a limited rotating inventory, and NPCs went around the shops during the day buying based off of loyalty. You can fill this shop with items made in your workshop, or any items really (but, perhaps, you could get small amounts of commerce guild prestige by selling actual proper workshop items from your town shop), and man it whenever you, possibly even hire someone from the town to work the stall for you? (Something that your spouse or child could help with doing, if that all is implemented.) You'd have to actually work to earn the townsfolks' loyalty by both making friends with them and also filling any commissions on time. If you fail to fulfill a commission from them on time, their loyalty would go down a lot, and they'd be more likely to buy from your competitors - other NPC shops. The entirety of this would require adding small micro-commissions that the townsfolk request a lot from you - such as wooden or stone furniture items, or even just collection quests, like bringing them some fabric or fruit or raw material, depending on that individual's habbits and needs and likes and what-not - but I think that that would be great, even without a shop stall to run.