Yeah, 300+ is way too much for that - you could almost buy an RTR Hardcore NTC3 for that much!
I would be very much surprised if the motor really was a Mugen (which, in turn is based on a Novarossi)
First, it's a .16 - Mugens are .12, .15 and .21
Second, I compared the two (.12 and .16) Cen motors I have in my garage to my Mugen MT-12 and there are no similarites except for basic shape - fin patters, carbs, everything is different, especially quality - Cen motor feels cheap by comparison.
Third - if it was a Mugen, the quality would be high enough that their sponsored Pro drivers would be running it, don't you think? Instead of the Pico?