For USD1000 a month, you will just live a life slightly better than the poor in most Asean countries. In that case, might as well stay home and only do short visitation to other country when you save enough to enjoy life like a normal tourist would.
Starbucks and McDonalds are not very good way to measure food prices or cost of living standards. Starbucks price really doesn’t vary all that much between all countries in the world: an European country Starbucks price may be 30% more expensive than an Asian country’s, but the average food price maybe 3 or 4 times more. McDonalds price varies depending on the sale tactics, local culture and interests in McDonalds food.. and qualities of food are not standardized for Big Mac among different countries, some bigger, some smaller.. For another example Big Mac has a longer history in Hong Kong than in Shenzhen or in Vietnam; however even if HK has the higher cost of living than the other two places, Hong Kong has cheaper Big Mac.. HK people have been eating at McDonalds since the 70s and are used to cheaper (and smaller) Big Macs.