Is $16 for a (non-meat) burger with no drink and sides a "ripoff", or just pricey?

I made a mistake a while ago when I went to this one restaraunt in Manhattan. I only had maybe 20 bucks on me. I figured I could get a decent meal and then some money for transportation.

Turns out the burger alone was $16-$18 once tax was done. I couldn't afford a beverage since they were like $2-$3 without tax.

The burger was nice and the portion size was good. But, I'm not used to such expensive burgers.

My local diner sells burgers + fries + a small salad for $18. At Burger King, I can find it even cheaper.

Is this a normal price for a high end burger, even if it's vegetarian? Or was I in a pricey area?