I agree that is the risk involved. Buying right before playoff time can be useful to ensure a title.
However, if the player addition will help lead to HCA, it can be an asset too. Also, winning more league games for ticket sales, etc.
There was a guy I wanted really bad last season. Sold for $125,000 around 1 week after all-star break. Sold for $255,000 right before playoffs. Had a $25,000 salary.
IMO in most cases the holding cost is close to the difference in sales price. But I would agree with you it really depends on the situation.
Overall its a great time to sell though if you don't need the player
