The loss at 800Mhz over RG8X is totally noticeable by ear, my old scanner antenna was RG8X, about a 60ft run. Changing to a newer antenna only made a slight improvement, going to new feedline gained three bars on the readout of my BC796D and took out all the noise.Running that expensive coax (LMR600??? Please) for simply receive is a complete waste of money as it's never going to be noticeable by the ear, and by using these not so great receiving scanners. If he was transmitting on VHF and UHF, then I would understand the need for it, but it simply looks as if he's receiving.
You could run RG8x for like $40/100ft. Especially since the distance doesn't look too far. We don't even run LMR600 or hardline out to our towers here in Arizona.
If you use RG8X your loosing many a dB of signal. Some people like to get all they can from their antennas, i am one of them also.