It doesn't set that precedent at, and in no way does it mean you now need to allow buying and selling of individual players.The real problem is the precedent this sets. If you allow this you have to allow trading Don'ta Foreman and $100 for Barkley, or Cooper Kupp for John Metchie and $200 (hey, they are both on IR, there's no competitive balance). If it's ok to include outside compensation in trades, you end up with P2W (pay to win) which as any gamer knows is a horrible model to run a platform on. The guy making 200k a year will think nothing of throwing $50 out to try to win a $5k payout but the small business owner can't afford to take those risks. You end up with a horrible competition model. I think the key is if all members agree up front that this is how they want to run the league. If they are all up for it then sure, do it, because they all forsee the risks. You're never going to get that agreement from an online league, but hey if you do, or if you're in a league with all lawyer or doctor buddies why not?
Again, it's not a trade. It's a complete franchise swap. A trade of players for money affects the competitive balance of the league. Swapping franchises does not. Totally different things.
Also, this idea that someone with deep pockets can keep getting over on everyone. Well, that's not true. Nobody is going to sell a great team for peanuts.