To be honest, if you're looking for a managed server you will not find one for $50/mth. Most reputable Management companies charge more then that just as Managed Services and excluding the actual server.
Some seasoned vendors out there to consider would be:
(research this company because they have an array of mixed reviews). If you're in Europe they also have a DC facility in Holland I believe.
Also, when looking for a VPS I would also ask to see what software they're using to deliver the VPS service. If the host is using the Parallels Virtuozzo Containers then that's two thumbs up
Parallels does have some advantages over the other VPS technologies such as HyperVM or OpenVZ. A few months ago HyperVM had a major bug that affected many VPS providers and their clients. The Parallels Containers offers the highest levels of density, performance and manageability.
Good luck on your search and let us know which host you pick when you come across one.