Small firms are investing significantly more time and money to seek federal contracting opportunities than they did three years ago, according to a new survey from American Express Open.

The average investment by the small vendors rose 49% over the past three years.

The average amount invested by the firms in seeking federal contracts in 2012 was $128,628, up from $86,124 in 2009.

Small businesses with 50 or more employees spent an average of $257,098 vs. $37,172 for small firms with fewer than 10 employees, in 2012.

The 684 small federal contractors were characterized as a representative sample.