Purchase price from eBay the cheapest place is $290 by the way, they both sides are the same. There is no left and right , the air shocks works for both sides. 
how did you know that you needed to change the strut? e.g., was there a sound indicator failure of the old one (if so, what kind of sound)? Did the driving feel change? Thanks in advance!
I’m slightly worried about the lack of any torque wrenches in this video. Saving $900 while potentially risking serious issues is a tricky deal. Thanks for sharing though, very clear video.