Within 5 minutes, our site was down.
The owner of the company negotiated with the guy, and he stopped his attack after receiving $400. A small price to pay to get the site online in our case. But obviously we want to come up with a solution that'll allow us to deal with these kinds of attacks in the future.
While the site was down, I contacted our hosting company, Rackspace. They proceeded to tell me that they have "DDoS mitigation services", but they cost $6,000 if your site is under attack at the time you use the service. Once the attack was over, the price dropped to $1500. (Nice touch there Rackspace, so much for Fanatical support; price gouging at its worst).
So, obviously, I'm looking for alternative solutions for DDoS mitigation. I'm considering CloudFlare (https://www.cloudflare.com/) as an option; does anyone have any other suggestions or thoughts on the matter?