Hi Justine, Me again - sorry!
I may have missed it in your lyrical support of Jab engines - did you fail to mention/cost that Rotax
Recommend 100hr oil / filter change intervals. From imperfect, aging memory, this means that Jabs will have 4 oil/filter changes to one Rotax. Cost$$$
In the same airframe, a Rotax of similar performance to a Jab (ie 80/80 or 100/120) will deliver markedly better fuel economy. Cost$$$
Resale of used Rotax 9's (TBO sales from schools etc) looks pretty healthy. Cost $$$
Just checked the approximate price of a Rotax 912UL (the equivalent of your Jab 2200) $30K - this is probably base price, so lets say $35K, a tad cheaper than the $40K you estimated.
Rotax 9's are expected to go to TBO (hrs) & well beyond, with little if any major life extending intervention. It can be a bit of a shock when the occasional one fails to deliver on this expectation but really all mechanical devices are subject to failure, it's just a matter of when and how much it may cost, in dollars, loss of amenity & crew health. (none of the later costed by you)
Dont know if Jab 4's have been around long enough to compare but the fact that you have costed sundry life extending intervention, would suggest that they still have some way to go from a reliability (crew health) perspective, loss of amenity (when aircraft in the shop for length repairs).
Speculation; Your costed list below for the 80 hp Jab ".......from $..." could easily blow out to a replacement engine every 1000 hrs😈
"Current jabiru pricing is
2200 Engine Gen 4
** Top End Overhaul from $5,200
** Full Overhaul from $6,300
** Bulk Strip from $6,300
**Does not include replacement of substantial items ie. crank,
cam , conrods, cylinders and heads. Engines must still be running..
so in actual fact the Gen4 is cheaper to overhaul every 1000 hours by about $15,000. "