Apart from the costs and different operating requirements it's always been difficult to design, produce & market a small GT in the 200HP range, that size powerplant is already well & truly entrenched in the industry with time proven cheap (compared to GT's) workable designs.
The Allison 250 series GT's have been very successful in the low 300's to mid 400HP range but costs are way beyond most light A/C operators budget to equip or re-equip their planes/fleets. Saw just the other day replacement compressor sections for same around $50-85K! Ouch! The two biggest "ouch's" for GT's are FOD & hot starts! Ive got more hrs behind GT's than I care to remember, just glad I wasn't paying for them:-)
I'd love to see a 200 HP GT and maybe I will before I hang up my flying boots (hurry up please I ain't getting any younger) but for now $$45-55K is still doable for a recip that any donkey can operate:-)