I'm in the market for a refractor and I just saw a NP-101 for sale for $1600.00 It sounds too good to be true. The seller does mention that the
"The lens is also in very good condition, as the pictures show. There is one small sleek on it, which did not come out on the photos, and is only visible from one angle -- it does not affect the views in the least. "

I have several questions.
1What is a "sleek" and what questions should I ask the seller.
2. Should I buy the scope and run