Because RRG is one of the few suppliers where spares for Prorack bars, I had little choice but to purchase from them. Unfortunately, their delivery fees are really steep. I bought a set of four 6mm grub screws for $21 and had to pay $19.50 for delivery - almost 100% of the item cost. It was a very small package. It's hard to see how $19.50 is a reasonable or justifiable delivery price for such a small item. By comparison, a set of 6" car speakers from many suppliers have a delivery fee of $10 - about 10% of the item cost. If you like being gouged for delivery fees, look no further.