Here, 67 Hail Hail rank Celtic’s most expensive signings in the club’s history. Celtic are renowned in Scotland and perhaps across Europe as a club who dip into the transfer market with a shrewdness and a sense of pragmatism. The Hoops are easily the richest club in the Scottish Premiership and have what it takes to splurge their bank balance on top-class talent befitting of wearing a green and white jersey. And while the club usually steers away from that lavish approach, there is the odd occasion when Celtic will spend big to get the men they want in their squad. The likes of Martin O’Neill,…