Before I found that there was a lot more money and a lost less hours and stress doing consulting than being a cubicle drone, I worked for a large hosting company.
Handling a DDOS attack is a piece of cake. We handled a few a week and this was in the early 2000s. We would watch the router traffic graphs and see a spike that might be eating 5% or 10% of our capacity and just grin. All you need is money. Your ISP needs giant pipes, spare server capacity distributed around the world and sharp network guys, and for the right price, they'll simply make the problem go away for you.
However the cost of doing this means that if $1500 to Rackspace sounds like a lot of money, you're not in this league.
If you're at the "less than $200/month" level for hosting, your best course of action is to not piss people off, and if you're attacked just hope you can wait it out.
The "up side" of having a small site with cheap hosting is that it probably won't actually do much damage to your business if it's down for a few days.