I think that first part might be obsolete. I'm running a new ~300 foot cable and found that the solid copper wire price is close to double from about a year ago. The big sticker shock was at Home Depot: $14.57 for 10 feet of sch 40 1" PVC pipe, and $8.50 for an 8 oz can of PVC primer.Cable is cheap but the digging trenches and filling in afterwards would no doubt cost a fortune.
Older ones can struggle and won't work well or at all on separate legs, the newer (2010) "G.hn" technology works well on separate legs but works even faster and more dependably on the same leg, I've read.Pretty sure ethernet over power doesn't require both units being on the same side of the phase, though I think it helps to maximize throughput. Lots of things interfere with obtaining maximum speed, but for running a single camera one wouldn't need maximum speed.
I just got a price of Au$80 for Loco M2. 2 of these would be cheap and most reliable where cable can't be laid. I had EoP about 60feet to shed and only got about 20 Mb with Loco M2 now get same as house about 90Mb and no drop outs.Just using the price of the Nano station, it's $247 (Aussie dollars). I would look at it from the point of how much would it cost you to run a cable to your garage? Cable is cheap but the digging trenches and filling in afterwards would no doubt cost a fortune. So, in comparison, $247 for the Nano Station v $1,000+ to lay a cable suddenly is not that expensive (that's how I would explain it to my other half).
Not to mention the improved speed, bandwidth, dependability and range you'd get with 2 UBNT radios linked with their proprietary protocol as compared to "standard wifi 2.4 Ghz".Was looking at Ubiquiti hardware when contemplating expanding my network 7 miles, but alas, line of site was complicated by trees and such. Might attempt something simpler first, like 700ft. I've already successfully linked a camera 500ft away using standard wifi 2.4 Ghz and an omnidirectional antenna. Would be even easier with a directional antenna.