I am confused, first you say the distance is over 50 meters, then you say it is approx 100 meters. If they don't want to pay for any hardware, I am not sure if you should be writing to us or the American Magicians Society.
Copper has a limit in the standards of a 90 Meter link and a 100 meter channel. To be safe I would install a fiber link and use media converters, but that would cost some money. You may want to try the copper, as you are at the fringe of the maximum distance and I have know some to work fine at about the 100-115 meter mark.
Joseph Golan, RCDD