A very inexpensive option is the basic digital multimeter sold by the Harbor Freight chain and on-line.
http://www.harborfreight.com/ Their basic meter seems to be constantly on sale for either $2.99 or $3.99, depending on the latest sale flyer. I've bought handfulls of these and have one in each of my vehicles and in our TM. I've also given them out to friends in the vintage car hobby as I try to educate them on cleaning up the corroded connections all these old cars seem to have.
Harbor Freight also has somewhat better meters for a little more, including a clamp on multi-meter currently on sale for $10!
Decades ago I was an instrument repairman for a defense contractor and was paid to calibrate 3 per cent accuracy meters that cost hundreds of dollars. I am still astounded that today meters with a greater level of accuracy have fallen in price to throw-away items. Just getting old I guess. ;-)
Arn