another option I've just found is VmWare's cloudfondry
here is a tutorial on how to configure it for play! apps
http://iambivas.blogspot.com/2011/08/running-play-framework-application-on.html
no pricing yet, but I guess there will be an affordable option...
edit: a new module for play
module: http://www.playframework.org/modules/cloudfoundry
