I agree with Ray. I got my 1 inch dial indicator first. Very useful still, but I find I use my 0.0005" DTI more frequently. Still, there are some things a DTI will not do because of the very short length of travel. If you can only afford one, get the dial indicator first, and save up for a decent DTI later. If you are on a budget, the DTIs from Harbor Freight and Grizzly are very servicable (I have 1 Grizz, and 2 HF units), and you can get them for about $10 with the right coupon. You'll also want to buy or make some sort of holder.