Example. GodBreakers looks interesting, but many reviews say its too short. I've added it to my wishlist that I will buy it when it gets more features or.. something. Something to clue the dev into what they could add or change in order to get more sales.

What purchasers put in reviews is good.. but you have their money already.

as far as the personal note. like wait till it hits x..

a tack on.. maybe add an alert me when its below $x dollars. Notification to be like hey! a wishlist is on sale and even better, it's below what you're willing to pay for it. I get maybe they'd use this against you to figure out how much they would have to discount.. idk.. still think it'd be more interesting and help the dev as well potentially.