Form timing analysis to prevent credit card fraud

Our site uses a Gravity Form and Bambora gateway to process credit card payments. To help thwart CC fraud and stop scripts an bots from mass attempting CC payments through our site, we would like to implement Time-Analysis on the form. Basically, if the visitor submits a payment when they have been on the page for less than X seconds, we want the submission to reject.

Has anyone implemented this? We’d like to do this in conjunction with reCaptcha and ‘maybe’ enabling honeypot.

Thoughts?