Readyheli sells the Kasama brand as do some other online shops. Parts are not too hard to get but sometimes you may have to wait on parts. Kasama is a small shop in Thailand, not Align or Thunder Tiger.
Price depends on what model you get. Check out RH website.
Vibration is/was a problem on the Srimok 90 for some. I think it was mostly builder error, although I'm sure this comment will offend a few here on RR.
If you want something different or you appreciate unique design, engineering and unsurpassed quality; the Kasama helis may be for you.