Hmm ..
A Tier5 with fully equipped Heal enhancers it makes 26.42 heal / sec. That is slightly less than an untiered Adj Mayhem. When Enhancer decay isn't factored in it has a slightly better base eco, but i take a guess to say it is slightly worse when enhancer breakage with 5 enhancers counts.
Statwise it is also quite similiar to the Fap 69 SGA, but the FAP-69 is no SIB FAP, anyway it delivers ok'ish results@level25, so i'd say these are somewhat comparable.
My assesment is that Jennson is pretty accurate with his logic, but a little high with the price. I think the range for a mid tiered Adj SK-50, give or take some for actual tier, tier numbers, and tt value, should be about +3k. That seems to me to be good starting point to negotiate up or down from, and looks to be the going rate based on recent past and current sales.