I haven't been to WDW since 1995, so I haven't seen the show yet. I have doing a lot of research for trip in June, and from what I can see, it should be pretty crowded. We are going with 2 other families, having a total of 4 small children with us. So, to not have to stand in line as long, it is well worth the extra few dollars to me. The restaurants that participate in this are Hollywood & Vine (buffet for $21.99 adult/$9.99 child), Mama Melroses (Italian, not sure of the price but a little more expensive the H&V), and then The Brown Derby which is the most expensive.
Hope this helps!