there was a time when it was normal to see prices on the ads... by now i only rarely see that. On the practical side that also makes it easier if you change prizes so you do not have to redo the whole vendor
I never put them on .. also if you put the pictures on flickr (great advertising to many people) that is against their TOS to sell and will spare you the time to make two ad versions for everything
I just recently started a store, and left off prices. 1) If my store lasts long enough for an item to go on clearance, I wont have to remake the vendor. 2) Flickr doesn't allow prices on stuff.
You probably want to make a Flickr pool (group) so that when any blogger or customer that uses Flickr wears your product, they may put it in there for you and all to see ^^
As you can see, I have put my vendors and stuff in it, and my bloggers (pretty new store so I dont have many) are beginning to put their photos into it.
As a consumer, I do like prices on the ads or otherwise clearly accessible (even by the payment menu is fine though)... as a merchant, I honestly don't do it. I've had to deal with the hassle after changing lol
So anymore, I just don't put prices on adverts because if I wanted to put that item on sale later, which sometimes I do after 2 years, it's just not the same quality... I'd have to redo