Sadly, 11300 is shared by Cairo, Tripoli, Addis, Khartoum and (I think) Nairobi...and many voices at night, all trying to talk over one another.
Not a good scenario.
We fly lower (FL270/280) as a result, and have no traffic problems, as we are always very heavy.
Besides...the slight additional block time is charged...accordingly.
Fuel?
Not a problem with the L10, with very efficient Rollers installed....even at lower flight levels.