I know it's all hypothetical at this point, but who is to say that if Burton was able to come over this season that he'd be after the 450k this year that he gets from next season?
He's on about 200k now, so it's possible he might be willing to remain on that salary this season if that was the only way to help make a deal work which would allow him to play FG this season.
Case in point, Luke Thompson came over early last season and would have earned a fair bit less (percentage wise) than what his deal was worth starting from this season..