Well, I consider my time very valuable.
I personally find that making a large quantity of fondant--along with the prep, associated clean up, and sometimes less than consistent results--to be a huge time sucker. With a 50% off coupon, my Wilton costs me $2.00/lb.--that alone is well worth not having to clean up. Given that in my area, PS is about .80/lb, marshmallows run about $1.00/bag (on sale), not to mention vanilla & crisco, electricity, water, dish soap.......
I also know that out of the package, the results will always be the same.
JMHO
Rae