I tend to buy preassembled cables, and almost always from Amazon from various vendors depending on the cable length/shielded construction I want.
For long cable runs and stuff that will be exposed to sunlight, I use Ubiquiti TOUGHCable Carrier (and toughcable RJ45 connectors) which I will buy from whoever sells it cheapest. Cutting in from the outside, you find the black UV resistant outer jacket, then a layer of wire mesh, then an uninsulated ground wire, a layer of some kind of metal foil, then a layer of plastic (probably cellophane), then finally the standard
cat5e pairs and a crosstalk divider. All those extra layers are easily cut away, and are not much of a nuisance. The twisted pair wires are just the right stiffness to be easy to untwist yet strong enough to enter the RJ45 connector without bending out of shape. Plus with Toughcable cable and clips, you get a working electrical ground connection on each cable which is nice for devices that are sensitive to electrostatic discharge. Ubiquiti radios are one such device... Stardot cameras, I have found, are another.
I'm pretty sure with Monoprice and other inexpensive bulk cable you just have the outer jacket (not UV resistant, but perhaps in-wall rated) and standard twisted pair loose inside. I find it hard to strip the jacket off this kind of cable without damaging the insulation on the twisted pairs inside, whereas that is absolutely not a problem with ToughCable due to all the layers.