I haven't been single for a long time but of course once was. When dating DW2B I was "house poor" and had to find cheap dates. One was go to the museums in Washington, DC (we lived near there then) since they are all free. The round trip subway pass was about $5 at the time. Eat a meal at home beforehand so you won't get hungry and buy their overpriced food/drinks. Or pack a lunch.

We ate a lot of spaghetti dinners while watching rented movies in front of the fireplace. If I'd worked overtime recently I could even afford a bottle of wine. She still swears it was the spices I put in the spaghetti sauce that made what happened afterward happen.... And that's free too!

DW wouldn't let me buy it, but I once saw a book titled "101 cheap dates" and in it were suggestions like eat a meal at home, then go to a high-priced restaurant and order just a dessert. You get the ambiance of the fancy restaurant without the high price.

State and local parks are usually free or very inexpensive if there is one nearby. At one park nearby I could rent a rowboat for an afternoon cruise on the lake for about $5.