Have you checked the parts for sale board? Bodywork available there.
Check sites like this: http://www.partzilla.com/parts/search/Yamaha/Motorcycle/2015/YZFR3+-+YZFR3FB/parts.html
Gives you an idea of what OEM stuff will cost. Depending on what bits you want to replace, there's enough info out there that you should be able to figure out yourself what kind of money you can expect to spend.
Check sites like this: http://www.partzilla.com/parts/search/Yamaha/Motorcycle/2015/YZFR3+-+YZFR3FB/parts.html
Gives you an idea of what OEM stuff will cost. Depending on what bits you want to replace, there's enough info out there that you should be able to figure out yourself what kind of money you can expect to spend.