private void Charge(InventoryItemPrice price)
 {
     GlobalModel.Gold.Value -= price.Gold;
     GlobalModel.Corn.Value -= price.Corn;
 }
 private bool VerifySufficientFunds(InventoryItemPrice price)
 {
     return(GlobalModel.Gold.Value >= price.Gold && GlobalModel.Corn.Value >= price.Corn);
 }