The two candidates running for mayor of San Francisco have made this year's election the most expensive in the city's history, spending more than $3 million between them. Assemblyman Art Agnos and Supervisor John Molinari have received contributions totaling $3,048,367 thus far and have spent $3,014,449, according to campaign finance records. The two candidates are involved in a Dec. 8 runoff after Molinari placed a distant second to Agnos in the Nov. 3 primary to succeed Mayor Dianne Feinstein. Agnos has spent about $1.4 million so far but has a campaign deficit of $162,856. Molinari has spent nearly $1.6 million, but he also has a $15,273 campaign debt. The records also indicated that many members of the local business community who supported Molinari have switched over to Agnos since the assemblyman almost won the mayor's race outright in the primary.