Hi, I'm looking to get 2 cameras to start. I've got lots of questions:
-Differences and price of IPC-HDW5231R-ZE and IPC-HDW5631R-ZE and IPC-HDW5831R-ZE
-Price of IPC-HDW4231EM-AS and IPC-HDW4231EM-ASE
-Is the IPC-HDW2231R-ZS the same as the IPC-HDW5231R-ZE minus audio?