Lots of services give you different prices depending on which region you appear to be from. Here is a handy wiki page explaining the concept.
This page documents the various services I use and their caveats.
Keep in mind that trying to cheat this system breaks TOS of practically all services.
Netflix has not only different pricing but the service they offer can differ. For example, in Turkey they offer a plan not available anywhere else, a very low-cost mobile plan.
You should be able to set up payments via any debit card for any region as long as your IP is from that region. For example you could use a Turkish proxy to have the service for half the price, you only ever need to appear from TL IP while you set up the payment method.
Netflix's library content is based on your current IP.
Steam's georestrictions have changed a lot throughout the years.
Regional pricing is set by game publishers and can vary a lot, but places with bad economy generally have cheap games.
Currently, at account creation your account's geolocation is decided. You can change it once a year.
You can only charge up or pay for a game through a valid payment method in the region you're buying the game in.
You can, however, activate a digital or physical steam gift card from any region, currency will autoconvert.
To activate a georestricted game:
Some games change their language availability depending on your region. Such is always noted in a warning on the store page for the game however.
Looks like Mexico is one of the cheapest regions to get membership through.
Regional IP only needed for payment. Takes any debit card if I recall correctly.
You can have a US, EU or RU account on Battle.Net(possibly more). This is decided at account creation time and changing this seems to require a valid ID and contacting support.
RU has most things for half the price, including World of Warcraft expansions and subscriptions.
While Battle.Net will actually let you use a debit card from any region, it will be declined and your payment refunded after a few hours. If you intend to have a RU account, you need to charge it up via a valid russian payment method or… game cards. Shady sites like plati.market have scalpers that sell such cards with next to no profit.