Before you spend a lot of money on a patent for your invention it is a good idea to get it evaluated by a professional firm. They can analyze the competition, the market acceptance and the cost of manufacturing your product, among other things. There are several places you can go for legitimate invention evaluations ( Beware of the scam evaluation and promotion companies!) The costs for their services vary generally from around $50 (for a very limited study of your invention) to around $500 for a very thorough and useful evaluation.

It is highly recommended that you get a market evaluation before you begin the patenting process. Most people, in their zeal to get their great ideas 'out there,' don't consider 'doing their homework' first and sometimes cause themselves a lot of grief. It is great to hear from someone who is doing their product development in a methodical way.

If you get a good evaluation before proceeding to patenting, you can often save yourself a lot of money, far more than the cost of the evaluation. These evaluations cover so many important things that product developers need to know about their new products, such as who (and what) your competition is, where the actual marked lies, how large the possible market may be, manufacturing cost vs. retail selling price, possible weaknesses in the product that could be corrected before patenting, even possible licensees, etc. Good evaluation services have contacts all over the world that they utilize in evaluating new products. That is something that an independent product developer would find very difficult and time consuming to do. These services will provide you with signed non-disclosure documents, so you can feel comfortable in disclosing your information to them. Visit these two sites:

http://academics.uww.edu/business/innovate/index.html

http://uiausa.com/UIAIAP.htm