I currently work full time as a Software Engineer working primarily in C#, we operate using test driven development and have thousands of test written to ensure our code integrity in the long term. I can use this experience to assist you in your testing processes.
Because of the nature of testing, it is impossible to determine the amount of effort necessary beforehand, after reviewing the details of the project I will provide you with a proposal of the costs, practices, and techniques I will utilize to accomplish your proposal.
I look forward to working with you now and in the future.