Consider that when going beyond com and net (the two main TLDs) there are suddenly many TLDs that could be used, possibly for cheaper or even hand reg. You have to ask why ".vip" is any better than the many others especially as "burger" has no relevance to "vip".
While you have a single keyword, which is great, it's on an unfamiliar TLD, and people may well prefer to have two words in com than the one in a lesser known TLD. Such as "BurgerKEYWORD.com".
Realistically it's worth reg fee on the basis you'll likely never find a buyer. If you find a buyer, even end user with deep pockets, they won't pay a lot due to so many other options.
Good luck though