To be honest, Brilliard, I cant remember, we will have to wait for Ruskie or someone else who knows to reply. I know it isn't the full amount, but whether you get it all refunded or not, I wouldn't know.
I have never done that, I have always thought it to be a false economy. Say, for example, you are looking at Fred Bloggs, who appears on a census with father, John. You find a marriage for Fred Bloggs and stipulate you only want it if father is listed as John. You don't get it, you just get the refund (full or part, whichever is correct!). In my view that hasn't helped much, as you don't know what the father WAS listed as, nor do you know anything else from that cert! If that looked like the right marriage for Fred, then I would prefer to get the cert. You may find, in my example, that everything matches - Fred is of right age, right occupation, address given is that of where you had him in last census, witnesses are the names of known siblings, etc etc , just that the father is listed as Henry, not John. So they didn't send it! But, yes it was the correct marriage, just that father has a different name, further investigation may reveal that Dad was actually Henry John and liked to alternate between them, or that father was John, but he died and step dad was called Henry, and the marriage cert ended up with a combination of first name and surname, I have seen that.
Best to research from as many angles as possible before sending for a cert, and then, in my view, Usually best to not stipulate any checks , but I know others differ in that view.
If you are stuck with someone in particular - before sending for any certs why not put the details on here and see if any of us can scratch around and find out any more info to narrow down which marriage/birth it might be?