Depending on your friend's tastes (and his date's), I might recommend Mae Ploy for Thai (located at Sunset & Benton). The ambience isn't great, but the food is excellent and definitely in your price range. It is very casual though.
I do not like the food at Masa. Bland. Boring.
Nicky D's is great for pizza but, like Mae Ploy, also might be too casual for a date.
Cliff's Edge might be your best bet, but wine would probably put you over your budget there.
If it's an afternoon date, Chango would be a great stop for coffee.
Didn't this say Los Feliz before? Well, when it did, my answer was:
I'm partial to Cafe Capriccio, since I had a blind date there four years ago and we're still together! But the food was good too.
Ignore suggestions for Vermont, Blair's, etc., since they certainly won't be under $25.00.
Carousel on Hollywood Blvd. is very reasonable, but not terribly cozy for a date.
In Silver Lake, you might be able to get out of Cliff's Edge for that if you order carefully, and it's a lovely setting.
Also good in Silver Lake for that sort of thing is Rambutan, although it can be a bit noisy.
If he must be in Echo Park, Barragan's booths are actually rather quiet and intimate, and the margaritas are good.