You may find yourself becoming an economic vegetarian, 'cause you can get way more food out of five bucks 'a vege than five dollars of meat -- for $5 you could get enough lentils and rice for a few meals (depending on your appetite and local prices). You'll find it difficult to eat healthily, cheaply,
and with regular meat. Might even go so far as to say "Choose two, 'cause all three ain't happening"
.
So look up some recipes for dahl, which is good because it is both cheap to make and very flexible (i.e. you can chuck in whatever vegetables you have to hand, or none at all if you don't can't afford 'em that week
), not to mention easy. Usually served with rice or a flat bread like roti or naan.
Chilli is another handy option, can be made with or without meat. Can be thrown together fairly quickly. Serve with rice or a maize-based option (cornbread, tortillas, or whatever strikes your fancy). If you make stuff with maize flour, try to get hold of and use https://en.wikipedia.org/wiki/Masa rather than corn that's simply been chucked through a mill, as it is more nutritious (and tastier, depending on, er, tastes).
Many Indian dishes are pretty cheap, so they're a good place to start. A web search like https://duckduckgo.com/?q=cheap+vegetarian should also turn up a lot of possibilities.