Lindy Roberts paid $15,000 of interest on her $300,000 acquisition debt for her home (fair market value $500,000), $4,000 of interest on her $30,000 home equity loan, $1,000 of credit card interest, and $3,000 of margin interest for the purchase of stock. Assume that Lindy has $2,000 of interest income this year and no investment expenses. how much interest expense may she deduct this year?