The 300 is by far the most economical of the classics and has a better payload/range ratio then both the 400 and 500 even if the 500 has a better overall range. When carrying a 200/500 load the fuel burns on a 300 are the same as the 500 with the option of carrying more when required,therefore Gnd Power the 300 should actually cost less than the 200 for Norfolk. It never ceases to amaze me how operators fight each other on routes that are obviously unviable for more than one operator with more times than not the imcumbent surviving after huge losses. I think if you do some research you will find that the repocession of VH-RON was more political then finacial which is backed by the fact they had the money to get another replacement aircraft.