Updates in Joomla Component

Looking for a developer that knows well Joomla and php to make a few updates to a Joomla component. Please respond only if you know Joomla. I have the complete analyses to send for evaluation of costs after receiving credible offers. The updates are adding some fields in some tables and make some new operations with these fields in the component that is working well, just some amendments, nothing complex. I want to know the developer proficiency to the price charged for anything unknown yet. An honest person and good programmer is what I look for. Thank you.