I would like to fence in my back yard. Nothing super fancy, just a black metal fence like you see everywhere. I got some quotes from some contractors and they wanted $6k+ (!!) to build the fence. I was shocked at the estimate prices given that my neighbors on both sides have already built fences, so I'd only have to do the back of my lot plus a little on the sides with a gate on one side (see dotted red lines below).
How hard would this be to do myself? I don't want/need to run a fence along the sides, so how would I go about integrating with my neighbor's fences? I didn't think it was possible to set the end posts right next to their fence as it would disrupt their fences, though I can't tie into their fences as they aren't mine (and presumably aren't on my property).
Also, what is the best way to match up the fences, given the height disparity?

