Don't be ridiculous, very few (if any) of us non-Spanish live in the San Francisco Bay area, nor Spain is the cheapest-rent-country in the world...
https://www.numbeo.com/cost-of-living/country_result.jsp?country=Spain&displayCurrency=USD
Apartment (1 bedroom) in City Centre 538.24 $ USD Conversion
Apartment (1 bedroom) Outside of Centre 405.77 $ USD Conversion
Apartment (3 bedrooms) in City Centre 834.51 $ USD Conversion
Apartment (3 bedrooms) Outside of Centre 643.81 $ USD Conversion
https://www.numbeo.com/cost-of-living/country_result.jsp?country=United+States
Apartment (1 bedroom) in City Centre 992.30 $
Apartment (1 bedroom) Outside of Centre 778.70 $
Apartment (3 bedrooms) in City Centre 1,699.44 $
Apartment (3 bedrooms) Outside of Centre 1,315.80 $
From my local area Denver, CO:
Apartment (1 bedroom) in City Centre 1,500.25 $
Apartment (1 bedroom) Outside of Centre 950.00 $
Apartment (3 bedrooms) in City Centre 2,606.20 $
Apartment (3 bedrooms) Outside of Centre 1,827.27 $
Spain: 3 months rent 1bd City (3*538.24)=1614.72 USD Conversion
Spain: 3 mo rent 1bd rural (3*405.77)=1217.31 USD Conversion
Spain: 3 mo rent 3bd city (3*834.51)=2503.53 USD Conversion
Spain: 3 mo rent 3bd rural (3*643.81)=1931.43 USD Conversion
US Avg: 2 mo rent 1bd city (2*992.30)=1984.6
US Avg: 2 mo rent 1bd rural (2*778.70)=1557.4
US Avg: 2 mo rent 3bd city (2*1699.44)=3398.88
US Avg: 2 mo rent 3bd rural (2*1315.80)=2631.6
Denver: 2 mo rent 1bd city (2*1500.25)=3000.5
Denver: 2 mo rent 1bd rural (2*950)=1900
Denver: 2 mo rent 3bd city (2*2606.2)=5212.4
Denver: 2 mo rent 3bd rural (2*1827.27)=3654.54
I think my original statement that Spain's 3 month rent thingy equates to generally less than US 2 month rent (first/last months) and holds true unless I am misunderstanding your statement, Dioxine?