But they were lucky, finding their dream home three miles outside of town on higher ground above the flood plain — a log house on a big lot where deer like to roam that's right on the Roseau River.
"Everything happens for a reason," Ost said.
Their real estate agent, Bob Brellenthin, said many families have been priced out of the market.
"I've had three deals blow up, to the tune of quite a bit of commissions that we did not receive, because we could not finalize the deal," he said.
Roseau is pinning its hopes on two things. First is the change to the 2012 law that Obama signed last week. It rolls back the instant increases, capping them at 18 percent annually for most homes.
More important is a flood diversion project due for completion in fall 2015. Flood insurance requirements will be eliminated for nearly the entire city once FEMA certifies the finished work, said Todd Peterson, Roseau's community development coordinator. But that could take another year, he said.
Relief could come sooner for Crookston, a city of about 7,900 on the Red Lake River, which recently completed its levee system. Once FEMA signs off, only about a dozen homes will be subject to the higher rates, city building official Matt Johnson said.
But Crookston real estate agent Shirley Iverson said the high premiums came as a "total surprise" to a lot of longtime owners who want to sell now and remain stuck, at a competitive disadvantage against homes outside the flood plain, she said.
Except for the premium phase-in, no relief is in sight for the southwestern city of Worthington, where 158 homes and businesses will see higher bills. A flood control plan for the city of nearly 13,000 is still in the planning stages and could cost $5 million.
City Engineer Dwayne Haffield said about 10 percent of its homes sit in a shallow depression that doesn't drain well, so they're at risk of basement flooding from heavy rain. The premium spike has made it harder to sell houses in that area, he said, and those costs are being reflected in lower property values.