Sue Smith saw a house advertised last week in The North West Star for $550 through a private renter.

"When I rang the owner, she said she preferred to rent to a company.

"But once I gave her all the information about my partner and myself, she seemed quite keen," Ms Smith said.

"She told us on Saturday that we could have the house. We talked about payment, organised payment arrangements and bank details. She asked us when we could move in," she said.

Ms Smith said the landlord told the couple she would contact them on Monday; but they did not hear from her.

"On Tuesday, she rang and said she hated making the phone call, but a company had offered her a substantially larger amount of money, at least $150 more a week and a five-year lease for the property," Ms Smith said.

"I understand it from her perspective. If I was a home owner I would want the extra money; but you can't take someone through the process, get their hopes up and then change your mind."

"I tried not to get excited. But when she talked about moving-in dates I was quite sure we had the house." Ms Smith said this was the second time in eight months this had happened to them.

Principal Licensee of Realway Property Consultants in Mount Isa, Kath Andersen, said this was becoming an increasingly common story.

"We have had people coming in telling us they have had landlords who had told them there were several people wanting to rent their property and whoever could offer the most rent would get the house," Ms Anderson said.

"We often have prospective landlords who tell us to rent their house to the highest bidder and we have to explain the legislation to them."

"If a house is advertised at a certain price, it has to be rented out at that price."