Last 737 200 would have been? I remember Boeing selling us a stack of them to replace the DC9's but I can't remember if they had JT8's or if the CFM56 hadn't already come in. That was about 1980.
Uncle Fester, I think you will find competition law treats marginal pricing (selling at a price that still provides a contribution to fixed costs) as predatory, but I'm not entirely sure.