Rightmove currently has one 3-bed property that's not above the LHA for the Brighton Broad Rental Market Area, which extends from Shoreham to Newhaven and a good 10 miles or so inland from the coast.
And I'd bet good money it's not even available to people on benefits. Trying to find a landlord who'll accept benefits is tough.
And I don't blame the landlords. When I was looking for someone to rent my flat for a year or so (while we rented in our new town and house hunted) I didn't want to rent to anyone on benefits - despite knowing what it's like from the other side - because of most council's policy of not rehousing anyone unless they've been evicted. This means that if you give your tennant notice and they can't find another place in time, if they go to the council for help, the council will actually advise them to ignore the notice, stay on and wait until eviction papers have been served and only leave when actually evicted. This costs the owner significant time and money.
In the end, I was talked into renting my flat to a friend on benefits and when we needed the flat back to sell, so we could buy stop renting and buy a family house for ourselves, we ended up in exactly the situation I feared. My friend couldn't find a place and the council wouldn't help.
Instead of evicting my friend (which we would have to do if it came to it) I offered to help with the flat hunt. I looked every day for 4 months, alongside my friend, for a place that would accept benefits. They were like hen's teeth. We eventially found one, my friend moved in for a day, on the first night the ceiling caved in due to damp and the landlord didn't come to fix it! So he was back at mine before he'd even handed the keys over.
In the end, he moved in with another friend when a room became available, so it was luck and not the suppsed safety net that got him a new place. Meanwhile I was looking at not having a house in the town we wanted to live in, in time for school admissions. It was a nightmare.
People who don't have to go through this system have no idea how tough it is and how the cards are stacked against people and the poor are punished for being poor.