Well it depends what you mean buy good quality. Any quality of
a transmitter can be good or bad depending on point of view.
(modulation, frequency, output power, power consumption, size,
stability, mono or stereo, signal quality, sexy looks...).
I've built tons of FM transmitters of all shapes and sizes but most
of them ware simple ones using 2 transistors. All of them have
really crystal crisp sound. Just make one, and then you'll know for fact.
How hard it is to put few components together and with no crossing
of signals? When I'm in bad mood, I make one in 10-15 minutes on
piece of cardboard. It's really that simple. Just do it...
Here is one that is really simple using only few components.
Don't expect too much from it though, but it sure does work...