@wakka02 about the free money thing, I'm sure money gained from a unique skill granted by the goddess herself would not cause inflation, most likely the fact a skill like that can exist at all means money is either given directly by the goddess herself in the first place anyways (whether through the "gold drops from monsters" trope used in old games, or a more realistic given to distribution hubs on a semi-regular basis method) or only can be made by humans with a similar blessing so any money MC makes with his skill would be accounted for in balancing the economy, and even if that's not the case, he'd have to use it quite a bit in order to make enough money to make a real difference in the economy given it'd take him a week and a half at his current rate to earn..well, 2 slaves of what I have to assume are intermediate quality...or a small bundle of low to mid grade potions at market price. it's probably enough to live comfortably off of, but not gonna break the economy any time soon. especially if adventurers help spread the money around by using it as they go from city to city for their quests. (MC uses money locally, locals place requests, adventurer does quest, gets paid, then goes to new town because new quest destination)
and I'm not putting the girls down for their looks or adventuring skills, but one's conditional xxx only and the other is no xxx at all (notably dropping their value, per the manga) and both suck at housekeeping/cooking (further dropping their value, again per the manga). and while they can probably read, that doesn't mean they can write, do math, or handle other more technical work, so there's a lot of areas they could improve in. (pretty sure they both fail on the math count, seeing how they couldn't even figure what their own worth would be in the slave market...or I suppose that could just be an excessive pride thing...thinking they'd be worth more than they actually were)
also, by comparison, he's currently only getting <0.1% per day of the value of a presumably high quality slave, aka Wendy