Definitely an option, the "rent a plane" thing.
Many RC planes have been found this way, even from a few thousand feet up.
(Particularly if it was a brightly colored plane, and not a very small one.)
If you have an airport nearby, it generally costs ~$50/hour or so to get a
guy with a small Cessna or something to take you up for a look-around.
(I know that price may be off, wildly... depending on who takes you up, and
where you're located on the Earth... so please, no flames )

The upside is... even if you don't find it, you got to go flying "for real",
and if you're lucky, you'll probably even get a turn at the sticks of the fullscale.
(Again, your mileage may vary... but I've had good luck in that regard)


Anyhow... if you do happen to spot it, pick out a landmark while you're up
there, or you'll have wasted the effort completely.