I started out with a 8 port POE injector that I got off Amazon. It worked fine, but I would occasionally loose a port (it would stop passing power). Once I lost enough ports, I decided to get a "real" network switch and ended up getting something used off EBay, (an Aruba S2500 48 port POE switch) for about $115. That would be my recommendation - do your homework and buy something used off EBay. For around $100 you can get a 24-48 port POE managed switch pretty easily. Not only does it give you lots of capacity, but will also allow you to venture into VLans should the need/desire every arise. I eventually created VLans on my network and it was easy to do and very helpful as well.
I really like the Aruba switch. It does not require any licensing to have full capabilities (something some switches require which is why you have to do your homework prior to purchasing). The only negative about the Aruba switch is that it doesn't provide enough power to run max POE wattage to every port. I can run 48 ports of POE, but if every port required max wattage, I wouldn't be able to do that. Obviously in a typical home setting, this isn't a problem. Not only do I not have 48 POE devices, the POE devices I do have (a mix of cameras, IP phones, Ubiquity mini switches, and Wireless APs) don't draw that much power. I run about 20 POE devices and still have plenty of power left to add more. In fact, I could probably run 48 ports of CCTV cameras because they don't seem to require anywhere close to the full 15w max power rating of regular POE.