I will buy stuff from xur because i am trying to collect all of the exotics. But i do earn a lot of my exotics. Mainly my weapons because for some reason i can't seem to get armor legit. still i have gotten the thorn, the invective, gjallarhorn, and super good advice from either exotic bounties and from random encounters. I did however get the no backup plans legit (if you want to count the exotic engrams xur sells) I did get the gjallarhorn from random reward for crucible. (i about shit myself)