Probably higher than you'd think, very rare for a defenceman to be putting up PPG numbers in the NCAA. Value might come down as he approaches his free agent eligibility without an ELC. Personally very high on him, and hope he plays for the Flames.
Goldobin I like and might get your foot in the door, but if Fox is being moved it's probably as part of a package for a more established young scorer.
As for the thread, Stone would be the most likely defender to be getting traded, probably for a pick or a promising young bottom 6 forward. Brodie I really have no idea what his value around the league is, this is a very capable player who is still on the right side of 30 pts in a down year and the right side of 30 years old with some years left on his contract. The only way Treliving should be moving him is for a sniper for the PP or a fast young RWer that has at least one season 40pts or higher.. If he gets moved for a middling 1st and some spare parts I'll be very disappointed.