You probably could have found a used propane stove for less than the conversion kit.
I never cease to be amazed at the almost brand new camping equipment I find at garage sales. People buy a bunch of expensive stuff, use it once or twice and find out camping really isn't there thing. The gear sits in the attic/garage/basement for five years then they sell it at a garage sale for pennies on the dollar.
$15 for the converter vs. $??? for a used propane triple burner. I doubt it, even the used triple burners (that are worthwile) are a heck of a lot more.