Ask HN: trustful VPN proxy provider?

My partner and I are currently running a Facebook application in China. As you may know, Facebook.com is blocked in China and that causes inconvenience. We consider to buy a VPN proxy service but there are too many noise when Google it. We need a VPN service that is trustful and secure, supporting multi-user (< 5) and at a reasonable price (we are startup afterall, < $50 per month is wonderful, < $100 is OK).

Any suggestions?