Is there an equal to hostbillapp ??
http://WHMCS.comhttp://Blesta.comOnApp, and a few others too.
How much does it cost to fix a bug ?? ( i guess there is price for everything)
I don't know what he's charging to fix 'bugs', nowadays, but yes, Kris generally charges for everything, even bugfixes if you ask before he addresses it himself.
Can anyone share the list of cloud and VPS plugin that is most stable and running without any issue in hostbillapp ?
Honestly, I will defer to what I recommended before. Check the refund policy, then test drive and if you find it to not meet your needs, then get a refund.
Is it real that one person fixes everything for you ?? and everything is on him ??
There used to supposedly be two people, then he added some support personnel to help out in his own forums, then he got mad because the community got mad at him and then he deleted the forums. After that it was a one man shop with just Kris - Now? I'm not sure.
Most people moved to other platforms like the one's I mentioned above, if that's any indication of the level of confidence that people have in the developer himself.
I hope that helps.