For example, Boondog's PCBs have extra header posts. The PCB Artwork is freely downloadable so that you can take a look for yourself. Boondog contracts PCB fabrication to Alberta Printed Circuits, a respected circuit board manufacturer. All PCBs, Kits and Assembled units you purchase are professionally made. You receive bounded Applications Manuals and companion disks with your Boondog order.
Some chapters are freely downloadable here.
Many companies advertise devices that looks cheap. But their products often force you to buy their special cables or terminal expansion boards at inflated prices. Boondog products always comes complete with cables, spacers, terminal expansion boards.