just put the price up to a price that you would be happy to do it for.
if that's £50, or £150 whatever it is, there will be a price that would make it worth the troublesome parking and gate!
we've had some houses, usually big ones that were under priced at the start, once it starts getting to me i put the price up to something that makes it worthwhile. you'll loose most of them as it means they've had a price hike, but the ones you keep become cleans you like.