Ok. Rough example: Let say some buyer has opportunity to buy player who needs 13 skill points for scout for 1T and has opportunity to send you offer that in start costs 8-10T + additional tokens he wants to offer to you. Why would he spend soo much? Is that small sp difference valuabe soo much?
On high level auctions you can buy various good players for 1T because there is no active managers which would bid.
I'm not saying that negotiations Q player aren't valuable, but you can't expect to sell player with equally good offer on high level and low level.
Besides that, don't forget on form. Even scouts or stronger players are useless if form is under 7 so those few skill points don't make great difference.
I've bought this season 9 fast trainers and few oldies and spent ~20T on all transfers. Now those fast trainers have 6* (3 players) and 7* (6 players). I've once bought player through negotiations 2 seasons ago and I'll never do it again.