home depot and lowes are awesome. My parents got mine from home depot or lowes I can't remember but it's heavy duty plastic and it was cheap and can fit a ton of stuff in it, it even had little compartments built in and its lockable and water tight. It even has little compartments on the outside top so I can put stuff when i'm not using it and even has two cup holders on it! I like it better than most tack boxes, don't have to worry about it getting mildewed or ne thing if it gets wet or worry about scratches.
"The horse you get off is not the same as the horse you got on; it is your job as a rider to ensure that as often as possible the change is for the better."