Fueling our Nissan Leaf (EV) costs us between $25 to $35 per month. The car my wife was driving previous to that was $100+ per month for the same driving.
Tesla supercharger stations use a completely different socket than other DC-Direct supercharging--they are meant only for Teslas to use.
However, there are plenty of other DC supercharging stations that use either the CHAdeMO protocol (Nissan, Mitsubishi, Toyota and Subaru) or the Combined Charging System (Audi, BMW, Daimler, Ford, General Motors, Porsche and Volkswagen). Note that not all of those companies have EVs to market, but they have agreed to use those systems. It is something of a "format war" right now, so who knows which protocol will win out.
Thankfully, ALL EVs sold in North America also have the J1772 connector for fast AC charging (7-10 hours for a full charge, depending on various factors).