I think in order to make a a determination on how much such a business is worth, we would need a little more information. Actually, a lot more information. Like a look at your balance sheet, income projections for future, years, historical performance, etc. One way to determine the valuation of the business would be to discount future cash flows. In order to do so, there is a lot of information that is needed.
In selling your business, depending on the value we are talking and the type of business, your buyer will want to do their own due diligence, which might involve them sending in a third party valuation team to perform a valuation audit.
As far as finding a buyer goes, you could reach out to a business brokerage firm. I know that both Inc. Magazine and Entrepreneur magazine also have areas where you can post a business for sale on their website. There are also websites that advertise businesses for sale.