Dave:

As to the sponsorships, it shouldn't matter the amount of the sponsorship. I would recommend no less than 15% if not 20% if you're taking on all the costs of obtaining and managing the sponsorship.

As to the marketing plan, you need to consider the complexity of the company first. I would recommend from $1,000 to $1,500 for the average small business (I mean SMALL with 50 employees or less).

Hope this helps.

Kent Capener
Capener Consulting, LLC
http://www.capenerconsulting.com