[mrweasel]

That can be read in two ways:

1) It's only $100, well worth the money.

2) Surprisingly little value was provide for all that money.

[jen729w]

I'm not sure how you'd read it the second way.

[mrweasel]

$100 per month is a lot of money, in that case "wow is that all?" must refer back to how little you got from it.