A high-priced showdown over Medicare payments will likely play out in an Iowa courtroom. A 58-year-old Florida man entered a plea of not guilty yesterday in federal court in Des Moines. Floyd Seibert — also known as Martin Mesquite — is charged with conspiracy and health care fraud. The feds say the man submitted false reports to get Medicare payments, and government lawyers are asking the court to seize over two-point-seven milllion dollars worth of the man’s assets. The trial is scheduled to start in early December in Des Moines. The office that handled the allegedly phony Medicare payment requests is located in Des Moines. If Seibert is found guilty, he faces big fines, and lengthy prison time.