Vultr just created their extra cheap plans.
2.5 usd/month for 512mb ram, 20gb ssd and 500gb bandwidth. This should be enough for a simple, 20-30 slot cod2 server.
If you want to sign up, please use my promo code. This will get you 20 usd in credit after you deposit 10 usd to the service. This means that you can run a server for a year there for just 10 usd.
http://www.vultr.com/?ref=6933630-3B