I used to use a $10 DSE cheapie and never had a problem with it but the leads eventually broke after about 5 years. When I was looking around for replacement leads I decided it was just as worthwhile to get a new multimeter. I am now using a CABAC multimeter which includes a cable tester which is worth around $40. I expect it to last me say 10 years. The DSE cheapie still works, by the way.

Yes, Fluke are up there with the best but frankly unless you are a professional you will never use half the features. I would take the $20 meter back to Jaycar and get a replacement if it's under warranty.

With a pinball machine you need to be able to check continuity (the number one problem to date with my machines has been loose wires which have been fixed with soldering), resistance, voltage and maybe you might want a transistor tester on the meter. But you can get all that on a $20 meter which will last you 5 - 10 years or more.