=COUNTIFS(Sales,">=499",Rollover!$O$10:$O$1318,[@[IC''s]])-COUNTIFS(Sales,">=2500",Rollover!$O$10:$O$1318,[@[IC''s]])

and

=COUNTIFS(Sales,">=2500",Rollover!$O$10:$O$1318,[@[IC''s]])-COUNTIFS(Sales,">=10000",Rollover!$O$10:$O$1318,[@[IC''s]])

and

=COUNTIFS(Sales,">=10000",Rollover!$O$10:$O$1318,[@[IC''s]])

The check boxes are found in

'MASTER INPUT SHEET'!O2:O283