I wrote a post a while back on why 'realistic' prices in video games are a really terrible idea and why.
Basically, it boils down to the idea that very expensive items in games, such as property, need to affordable within a span of dozens of hours, not decades as is the case in real life. Which inherently means the player is able to earn relative income very, very quickly. Which in turn inherently means reletively petty items, such as food and weapons, need to be priced far above any 'realistic' price to avoid becoming essentially free and thus make the whole mechanic pointless.
And thus we have claw machine games that cost 500 bucks to play. As it should be.
Eh. Who says the player has to buy property? The adventurer is only looking to buy weapons, armor and supplies.
A lower tier house in America cost under $100K in many markets. Do you have any idea how many high end guns you could buy for $100K? Enough to arm you and a group of ten companions to the teeth. Also, for the record, property does not cost all that much in Medieval settings. We aren't talking about structure built to code with plumbing, electricity and insulation. Unless you are talking about being able to stroll up and purchase a castle <ahem - Fable>, then even buying property isn't that far fetched. The difference is that a Soveriegn is more than a commoner makes in a month, while it is a pretty puny reward for saving a kingdom.
Not to mention the hero dives into long-forgotten caverns, kills bandits sitting on plunder, find lost cities with ancient treasure and other similarly unusual things. If there is a get rich quick scheme, it's being able to fight your way into the middle of somewhere totally inaccessible and looting it blind.