A $6.95 "For Sale By Owner" sign may have been the second-best investment John Piazza ever made. His best may have been his little house in Colonial Beach.

An hour after Piazza put the sign up in the yard of his home at 604 Monroe Bay Ave., a golf cart stopped. A Stafford County couple got out, looked the place over and asked "How much?"

Two hours later, Piazza had in his hand a deposit on a $208,000 deal for the 1,100-square-foot concrete-block house with a pier.

He paid $119,000 for the place in 1993.

"It's unbelievable," Piazza said of the booming real-estate market in the old resort town on the Potomac River.

Real estate is selling fast and for top dollar. Building permits for new houses and renovations are way up. And developers are poised to rebuild the town's down-at-the-heels boardwalk area and to create a new golf-course community at the edge of town.

Latana Locke and Bob Swink couldn't be happier. Both are real-estate agents in Colonial Beach enjoying record sales this year.

"Last year was very good, but we've closed more properties already this year than last year. This year will be our best year in 16 years of business," Locke said.

For Swink, "the best year we've had in 10 years" has one downside.

"We need listings so bad," he said. "We only have four or five active listings still available. We had two new listings this week and both sold before the week was out."

Mayor George W. "Pete" Bone Jr. said the real-estate boom is the result of the town being "discovered" by affluent residents of Washington-area suburbs seeking vacation and retirement homes.

Michael J. Wardman is one of them. The scion of a family long prominent in Washington-area construction, Wardman bought a weekend house in Colonial Beach and "fell in love with the view of the river and with the town."

The Wardman Cos. recently bought two adjacent commercial properties in Colonial Beach's rundown downtown: the former Hop's Place at the corner of Hawthorne and the Boardwalk and the former Olga's Art & Framing at 10 Hawthorne St.