You can't even get into a concert these days for much less than $20 or $30. So when you consider that a show by an act like Cheap Trick or Big Bad Voodoo Daddy is included in the $3 admission fee every Saturday and Sunday at Gulfstream Park, the economics are evident. Also included for that measly two bucks is parking, a race program, and -- oh yeah -- a full day of high-caliber thoroughbred horseracing. All of the dough you're saving, of course, is fodder for betting on the ponies or for spending at the track's restaurants or well-stocked snack bars and cocktail counters. And in addition to the concerts, another track perk is Showtime at the Inside Track Room, a free live program during which patrons learn how to wager, held every Saturday and Sunday at 12:30 and 3:30 p.m.