$.99 kids' combo with the purchase of any medium or large sub or salad. 2020 Firehouse Subs. This offer valid with coupon at 620 Butler Crossing, Butler Township, PA 16001. Prices and participating may vary, see restaurant for details. Limit one per customer, per visit. Not valid with other offers. Substitutions or additions may result in additional charges. Exp. 4/10/20. $99KIDS