Booters cost like $5/month and the pools need corporate grade protection to counter them; it's not cheap (2-4k/month for TCP applications like Stratum). If we manage to knock off 50% of the nodes, the booter price might go to $10/month or something so it's still a losing battle. These aren't the sophisticated attacks that mtgox has to deal with, but a simple UDP flood. Most hosts that offer DDoS protection, from my shopping experience, max out at 10Gbit/1-5MPPS, and I consistently saw attacks stronger than that with CNC (peak was 22Gbit, 75% of the attacks were over 10).

Some prices for dedicated DDoS protection I found: (not shared like awknet or VPS)
Staminus     $1k/month for 10Gbit/1MPPS (not strong enough)
BlackLotus $675/month for 10Gbit/6MPPS
Some other  $1k/month + $4k setup for similar

The solution I've come up with is to just use a suite of reverse proxies:
buyvm/etc VPS (10Gbit/5MPPS)
Minecraft-oriented VPS/Dedicated (Varies)
Cloud Load Balancer

For example, I used an amazon elastic load balancer and some micro instances for forwarding. By using the ELB, amazon soaks up the packet floods and does some filtering. I also use cloudflare free, but there's a risk. If your site gets a http-layer attack, and you're not on the 200/m plan, cloudflare will change your DNS record and effectively direct the traffic to your server. The pro is a packet flood goes to the CDN node, and that's not associated with any single domain, so it blocks those (you can route longpolling through cloudflare since it's HTTP traffic)