It’s impossible to give an adequate quote and set of options without detail about how the technology works and a better sense of your business plan moving forward. The variety of options is extremely large. The cost to draft and file a patent application could be from $500 - $30,000 (US) depending on a variety of factors.
You should talk with a patent attorney about your options and the costs. Drafting and/or filing the application yourself would reduce costs, but is not advisable if you want viable protection.
Also, you might find the following resources helpful when comparing patent attorneys and quotes for patent applications:
http://www.patentsdemystified.com/is-it-safe-to-use-legalzoom-to-file-a-patent-application/ (Starts with a discussion of why legal LegalZoom and other cut-rate or do-it-yourself services are a bad idea for patents, but also helps you understand how not to over and under-pay for a patent application).
http://www.patentsdemystified.com/chapter-8-picking-a-patent-attorney/ (Resources for comparing and screening patent attorneys).