An indexable-insert drill can produce a hole four times faster than a spade-drill but may cost (with inserts) 50% to 75% more than the equivalent spade blade and holder. For making only a couple of holes, the extra cost is not justified.
Manufacturer's charts will help determine the best feed and speed to run the drills. For example, a 1 f-in. hole is to be drilled in 4140 steel annealed to Bhn 275. For the spade drill, speed is 80 sfm; feed, 0.009 ipr; and spindle rotation, 204 rpm. For the indexable-insert drill, speed is 358 sfm, feed 0.007 ipr, and spindle rotation 891 rpm. Determine the number of holes needed to justify the extra cost of the indexable-insert drill. Some additional cost data are given below.
Ignore tool life and assume that the blades and the indexable drills make about the same number of holes. (Why is this a reasonable assumption?) The holes are 3 in. deep, with no allowance needed. Cost of drills:

Assume for this example that a $45/hr machine rate includes the cost of labor and machine burden.

Spade blade $139.00 holder +21.90 per table $160.90 Indexable-insert drill $273.00 dril + 12.80 per two inserts $285.80