It seems like for fast food chains, dropping $10 bucks per meal or person will net you a few bucks back in change unless you're really trying to just get the least expensive option. Namely, no drink and no sides and no dessert. My baseline is Sonic with their Grilled Cheese sandwich, which isn't all that great, but you can usually ask for lettuce and tomato and I don't think I've notice an up charge. This runs a few dollars(ish) before tax.

Asian places seem to run a little over $10~$15 for a "plate" but you also get what feels like a pound of rice, veggies, tofu/meat. Probably the best deal as far as weight/price. Not including "buffet" style Asian places because I haven't been in one in 10+ years.

There's a bunch of non-chain Mexican places, brick'n'mortar and food truck, for around $5 bucks can get a few tacos which is alright but around $10 will get you a full place with a side of beans and rice as a side.

Its been too long for me to feel confident about my $20 a plate at a casual dining spot that I have in my head.