Dear sir.
Thanks for offering me a chance to get a job.
I've worked as a programmer at several companies for 10+ years.
I fully understand what you want.
I am a programmer and computer expert.
If you want, I will send you my resume.
As to your project, I am quite certain.
Don't worry.
I will take rid of your worries.
At least, let me see your project. Maybe I can offer you a technical support.
It's not an auto bid.
P.S. : maybe we can come to an agreement with more reasonable price.