Why R44 - Faster (5-15kts), AVGAS 60 LPH Vs JETA1 100+ LPH, Obviously a lot cheaper per hour to run (half the cost), Piston engine Vs Turbine (see above re turbine cost), brand spanking new Raven I Vs 30+ year old B206, cheaper component costs on average.... cost effective platform.
Why B206 - Extra seat, Turbine power, big baggage compartment compared to under seat boxes in R44, better utility/camera ship/airwork etc. platform (can remove seats, sling more, nose mount camera etc), more payload......
As a private buyer.... unless you have the extra coin to spend on B206, R44 is more economical for what you want to do.