Its not easy to find a 512MB ram VPS with 15Gb storage for $5 a month, but since you are willing to pay annually, You can contact providers and ask for that price, Your best place would be lowendbox though
Your best bet is to look around in this communitys Buy&Sell section where the company's post there current promotions and such as a advertisement with discounts and promotioanl coupons.
I also suggest you check out lowendbox.com, but when going there I wouldn't believe everything you read, my personal view of that site is biased on one person's thoughts of one company, if you are interested in a company there before ordering I would post a topic here with the company name you are interested in and get some live feed back from this community, it's more active and more 'respected', and real feed back here.
I just overlook lowendbox briefly to view different company's that come out and different deals they are doing, i'm not saying everything you see there is wrong or a lie I wouldn't just make that your only place of judgement of what you see there.
I needed something for a family member of mine, and they where not to sure of the internet scene but needed some hosting solutions to do what they needed, and they came to me searching and hired one of our team members to find them a solution and manage there internet presence well, I found the company from webhostingtalk and went with them, and they have been nothing but great but when I seen what the lowendbox administrator posted on his blog there was completely wrong, and very biased to the company because I assume he didn't agree how the company operated.
Do you have any other requirements?
OpenVZ? Location? Control Panel? IRC Allowed? VPN? What's your use for it?
These things help when asking for references for hosting options..