To avoid being fined because of this blurry market demand rule, GI could do what an online basketball game I belong to does. For each player on the transfer market, they tell you what he has been going for. Example: "23-24 year old Centers with 9 blocking have been going for 10K to 20K recently". They also list the talent level, but it's not a secret like it is here.

It would also stabilize the inconsistent bidding on players of similar skill levels. Which could be good or bad depending on which side of a bid you're on.

easiest way to stabilize the market :
Players get donated to free agency instead of being sold

Now there's a thought........when you get enough money, just buy up every high talent player that comes down the market and fire em if you don't need any more. Keeps talent out of the opposition's hands