Read estate agents will always try to get an offer out of you. Did you notice that on any inspection the thing they are obsessed with getting your name and number? The reason they do it is to be able to ring you and say: “Hi Drew, its Mike from the real estate agency, did you like that house? Are you ready to buy it? Do you want to make an offer on it?”.
If you really liked that agent and want to do him a favor – go ahead and make an offer. The agent benefits whether your offer is accepted by vendor or not. If the vendor wants more money than you are prepared to pay for the property – your offer makes the estate agent look good, because his advertising worked, it obviously brought a potential buyer that made an offer. Also, should another buyer get interested in a house and ask the agent: “Have you had any offers made on that property” – the agent will say “Yes, we were offered this amount and the vendor didn’t take that offer”, to make you go higher.
If you think about it, this way agents turn any private sale into an auction. The offers are used as bids, if you want the house – go higher. The only difference is that in auction you see the bids and in private sale you need to guess, because legally agents can’t tell you how much other buyers offered for the house.