I just found my old airline tickets on United PDX-SFO-OGG from my honeymoon -1980! The price was $450, per person in economy, and this was in 1980 dollars which according to Google $1 in 1980 is worth $3.81 today.

Clearly competition as well as advances in aircraft and other issues have pushed airfares down significantly over the years. I don’t see how this merger would raise airfares because their combined force would only be 38% of the market share.