Dear Sir,
I have read Project Description & checked the attached document for the bugs. I understand that you only want to fix the bugs but since this App is not developed by our team, so we need to add some Man-Hours for the understanding of existing code, which increase the estimate than your budget.
Please let me know, if you are interested to work with us, we can then discuss further to move forward.
Our current bid is just a placeholder to submit the proposal, as we still need to finalize the scope of work.
Look forward to hearing from you.
Regards,
YK
LEADconcept