There are many things that one can do on a date that cost very little. A slice of pizza and a day in the park, are not so costly. Packing a picnic lunch is nice also. For an indoor date, try to be creative. There are museums of all types, for example. These things don’t cost $100, but they DO give you a chance to get to know each other.
I am opposed to lounge dates. Lounges are sleazy places where guys are picking up women at the bars, people are often not dressed in a Tzniusdig way, and the stench of smoke clings to your clothing after you leave. At least it was like that in my day. Which is why I never stayed very long. I cannot imagine it has gotten better with time.