I have to agree with Dave & Jinx

What needs to be considered IMO

Is what kind of bike can you get for 10K

Will it be as good as your current bike with that 10K spent on it

If the answer is no, then you have your answer

But if the bike you have now isn't "in your soul"

If it's just "a bike" that wont be missed or mourned

Then no amount of money spent on it will help

But if it's part of the "family" then it makes "economic" sense at least, to upgrade it

If you fancy the idea of a "new bike" then go ahead & spend 18K