Subscription price is probably irrelevant. Looks like that's just the price at the beginning of the period, because in most cases it matches the FMV purchase price of the previous period.
There's a 15% discount between purchase price FMV and purchase price. My wife is in an ESPP that also gets a 15% discount. Her discount is shown on the W-2 every year in box 12, code V. The 1098 I receive from the brokerage when I sell shares doesn't factor this in and lists the tax basis incorrectly(as purchase price), so I always have to make an adjustment on my tax return and add in the discount, essentially making the basis purchase price FMV.