In the Auction House bidding you'll bid against Managers from all levels. The cash price each manager pays scales with the manager level. So lower level managers who have less and earn less pay less for their bids and if you see a manager many levels above you bid for the same player keep in mind his bids are scaled to his level. He will have a lot of money but his bids will also cost a lot more than what you are paying.
Also there's no perfect time for bidding. You have to be consistent in the search of good offers and eventually you'll get one.