My Ntorq engine seized!

Hey guys i needed some suggestions, so my 5 yr old ntorq stopped out of nowhere while i was completing my 200km ride. My stupid brain didnt thought of changing the engine oil before start of the ride thats the reason why it stopped. I was stranded in a unknown place. I took help from some locals and they linked me up with a local mechanic. It was late so i had to keep my scooter overnight with the mechanic today he called me and said that my engine is seized and the repair would cost me around 7 to 8k. Should i take my scooter from the local mechanic to a authorized dealer or repair it with the local mechanic. And also please let me know how much it can cost if the engine is actually seized. Please help me with it.