In the early rounds, when points are low & better guns are needed, the fire sale is a plus.
However, in the later rounds when everyone has good guns and have considerable amount of points I would ignore it, especially if it comes during a zombie hoard.
Trying to get it then, may cost player(s) to go down, losing costly perks & resources of other players i.e. monkey bombs to be thrown to revive down teammates, excessive use of the precious few thundar gun ammo, etc., Not worth it.
IMHO