Dear madam/sir,
I have 11 years experience with web development, mainly in php. I have done few projects on zend and magento, and am able to dig into someone's code and look for issues.
However, if overall time spent on your problem reaches 20 hours, I would like to have my bid paid completely and I would request another payment according to what was found.
Thank you for considering me,
Best regards,
Milan Bilas