Property taxes are relatively independent from the absolute value of the property. Only the relative value of a property to other properties in municipality determines property taxes.
In Nevada, it's a percentage (approximately 0.5%, varying from city to city and with other conditions, like commercial usage) of its assessed value, which is 35% of taxable value. Taxable value is the market value of the bare land plus the replacement cost for all improvements on the land, less depreciation.
The cost of running a city is largely independent of house prices, so if the real estate market crashes there is no getting around that municipalities need to increase tax rates to meet their cashflow needs. People may not like that they feel they are getting ripped off, but the existing infrastructure has relatively fixed ongoing costs to maintain.
Ok, where does the percentage come from? It is an arbitrary number set by the municipality to collect enough money from the property owners. Basically, if the city needs $100 million/year to operate it is just going to tweak the tax rate to hit that income number.
For example, in Vancouver the residential tax rate is around 0.15% and homes average around $2 million. Where I live which is a few hundred kilometres away the residential tax rate is around 0.5% and homes average around $600k. If you do the math, for both places the average place has $3000/year in taxes due — which is totally independent of house costs.
What does make the difference is if your house is more expensive than the average house. If you have a $2million dollar house in the place with 0.5% tax rate you are paying $10000/year in taxes despite your counterpart in Vancouver with a $2million dollar house is paying $3000/year.
I get this can be different across the world, but that is generally how it works in Canada.