To find out how much the wool costs, we need to multiply the price of a yard of nylon by 3, since the wool is 3 times more expensive. So a yard of wool costs $3 * 3 = $<<3*3=9>>9.
To find out how many yards of wool Caleb bought, we need to divide the total number of yards by the number of fabrics, since he bought the same amount of each fabric. So Caleb bought 68 / 2 = <<68/2=34>>34 yards of wool.
To find out how much Caleb spent on wool, we need to multiply the number of yards of wool by the price of a yard of wool. So Caleb spent 34 * $9 = $<<34*9=306>>306 on wool.
To find out how much Caleb spent on nylon, we need to multiply the number of yards of nylon by the price of a yard of nylon. So Caleb spent 68 * $3 = $<<68*3=204>>204 on nylon.
To find out how much Caleb spent in total, we need to add the amount he spent on wool and the amount he spent on nylon. So Caleb spent $306 + $204 = $<<306+204=510>>510 in total. Answer: \boxed{510}.