I think every country should have affordable decent food and even some of my cheap eating hang outs in London have closed down. These places were popular for the food they offered which was a limited menu, but that helped keep the prices down.
In SA on certain days places have specials that you can get serious bargains like the one Portuguese restaurant on the 21st of each month offers Prego's for R21 which is like $1.20 that come with a side salad and chips. Other places have lunch time specials for under $5 and I guess they make it up on the drinks you order.
Eastern food like Thai and Vietnamese has always fascinated myself and one of these days look forward to visiting and sampling what they have on offer. That Bo Ne looks simple yet it would catch my eye for sure.