Inexpensive shotgun recommendation for beginner trap shooter?

I've been recently getting into rifle and pistol shooting, but my father has really expressed interest in trap shooting this fall. He owns an old O/U gun that I've always loved, but I am hoping to acquire one of my own so we don't have to share.

He and I have both said that if we really get into the sport we'll look to drop several thousand dollars on nicer shotguns, but for now I really just want something inexpensive but reliable. Does anyone have a recommendation?