I don't know about calling their sales a con. I'm always on the lookout for premium cabin sales. BA seems to have them more often than any other OW airline.
I put my ceiling for J class at ~$2K. I just booked my second J trip on BA to EDI just about at my max (Using the AARP discount). Last year I was able to go to LHR for about ~$1600 due to a sale. I think anything $2K or under for J class is a fair/good price. I guess it's what you're willing to pay