Amazon offers the Fisher-Price Thomas the Train Wooden Railway Reg and Percy at The Scrapyard Playset for $39.99 with free shipping. (Toys"R"Us charges the same with pickup.) That's the lowest total price we could find by $23. It features Reg and Percy vehicles, a cargo car, magnetic cargo, and wooden buildings and rails.
Update: The price has increased at Amazon; however, Toys "R" Us still offers it for $39.99 with in-store pickup.