funny that this thread was just started.
i used to cut my bars with a pipe cutter my office's maintainance man left in the breaker room on our floor (it was adjacent to our data center and subsequently pretty big, so the sysadmins all keep our bikes there).
it was big and heavy duty. i cut no fewer than three bars down to size using it with no issue. it was really good and effortless with a remarkably factory-smooth cut every time.
i needed to cut some moustache bars down today, but couldn't find it; turns out no one had seen it in over a month. i then went to the hardware store and picked one up. i had the choice between a 9 dollar one, a 16 dollar one, a 29 and a 33 dollar one.
i went with 16.
i was able to cut my bars, but not easily. the left is 1/2 cm shorter than the right, and the ends are ****. i'm going to have to file them down before wrapping them (cloth), and the pipe cutter is destroyed.
my advice: pipe cutter AS LONG as it's good (i'll probably buy the nice one sometime this month). if you don't have access to a good one, use a rag wrapped around your bars in a vice clamp and a fine toothed hacksaw.