from looking at the tie it doesn't look like a 5 of 7-fold tie. It looks like a very basic/normal construction. Personally I think $100 is too much for this tie, but then again, I would have to see, feel, and tie it.
Besides the price, I do like the tie. How wide is it? Looks like 3" to me.
I am from Germany and have been joking with my employees that German is the most beautiful language. They worked hard to prove me wrong today and they created this... I thought you guys would appreciate it as much as I did. What's funny, I actually design/manufacture ties...
image source via Bows-N-Ties
Not a problem in terms of pattern. But I would suggest adding slightly more contrast (light and dark color) from shirt to suit. Typically you want to combine patterns that are different in scale. This is the case in your outfit b/c the checks are much larger in scale than the stripes.
Your co-worker is wrong!