I have deployed my app on Heroku. My app needs mongoHQ and delayed jobs workers. Heroku charges 0.05 cents per hour for each worker. Monthly bill is estimated around 354$. I was looking for a host which might come cheaper than this. My requirements are : memcached, mongoHQ and delayed jobs.
just install everything yourself on a vps. linode is $20 for its smallest instance. EC2 for a small instance for uptime during a month is about $80. This is all dependent on your traffic.