If you have a soda habit, cut back by drinking a smaller size for a week or two, or mixing half regular soda with half diet soda or club soda to reduce your calorie and carb intake. Aim to go sugar-free: Water and club soda (including fruit-flavored types) are ideal and diet soda is an option.
In summary, Microsoft Dynamics GP will cost you $3,000 to $5,000 per user, multiplied by the number of users and third party products and annual maintenance combined for an On Premise solution.
A friend at a small business asked me the most cost effective way to buy SharePoint for internal use and demonstration. I suggested the Microsoft Action Pack which is part of the Microsoft Partner Program. In the US, the program fee is $475 per year. There is also some paperwork involved, which can take time. The benefits for your company far outweigh the time and money.