shop owner told me that she has customers who toss out all the kit
thread and purchase DMC. Does anyone else do this?

I do it all the time- so many kits have floss that I just don't want to work
with. In fact, I just bought a kit that I'm going to switch out the floss and
the fabric- neither are very good quality and the project is large and
involved, so I want it to be the best possible quality materials.
So, I paid for a kit and am only using the pattern! But, I couldn't find the
pattern separately, so that was my only solution.
SueS