Hello,
My name is Rui Pimenetl and I've more than 6 years of experience in development of web automation tools.
I've read your complete project description and I feel very sorry for that situation, and I'm very understanding, so I can imagine that your budget is really low now, an I wont ask more than 50$.
Please let me know the URL of you're store and I'll be happy to provide you a demo with no comitment.
I assure you my solution wont stop working after a few days.
I'll be waiting to hear from you, and hopefully you can let me work for you on this :)
Best Regards,
Rui Pimentel