The critical parameter of a cheap FM-handy (or even a more expensive one)
will be the dynamic range. At my station the strongest local station
at about 40km) is 70dB stronger than my 'QRSS-noisefloor' at low QRN,
is even 90dB above this level.
I'm afraid that a strong station will 'close' the entire band when using
FM link, if you cannot keep DCF39 out of the passband things will be even
If you can hear/see signals on your local setup the FM relayed signal will
be only a tiny bit worse due to additional distortion introduced by the
additional modulation and demodulation processes.
There is no additional dynamic range needed on the proviso that the receiver
is the same or comparable.