Believe me when you SELL them you will be greatfull of any bids and if its a collector or dealer that pushes the price up a Β£1 ($1) is all the same regardless of who gives it you.
Richard mentioned pennies selling in the Workman sale of which i know a collector bought 7/8 and a couple of other collectors quite a lot between them both, if those three people hadnt bid then most would of gone for a lot lot less.
If Atlas did buy some or any other dealer from the Workman sale, they had the same oportunity and the same pound notes as anyone else and what they chose to offer them for after the sale is up to them.
Buying something for Β£20,000 and then asking Β£40,000 doesnt always work out π.