While I would agree with you if they all were USB printers, many printers, and Im assuming he will have some older ones, which is why he mentioned IP Based solution would have a NIC. I would suggest daisy chaining a switch of your router. I am assuming alot here, you made no mention of running DHCP which I have to assume you already have in-place or why else would yu be asking for an IP based solution right?
The other alternative, if they are all newer printers is like Zedric said, using a USB hub, and attaching it to a PC (if its USB/USB) or to the switch (if its USB/RJ-45). Now this doesnt work obviously, if you dont keep your PC on (USB to USB option). If you do have all USB printers then this would be the most logical solution.
May I ask why you have 7 printers?
hehehe