If you are looking for the services of an SEO reseller, it should be noted that as in any industry, not all of these professionals are necessarily alike in their abilities, reputation, or rates charged. With that in mind, there are indeed a number of different reseller options out there right now, and the sheer plethora of candidates out there means that you are fairly likely to find a decent reseller in your price range.
However, you should first ask yourself what type of value you expect your reseller of choice to provide once the transaction has been initiated. For example, you should sit down and ask yourself not only how much you can afford to pay any reseller you have in mind, but also what type of results you expect in return from said professional in order to make the price worth it in the end. Determine how much your average profitability would need to rise in order to justify the expense of hiring an SEO reseller in general, and then set a deadline by which your goals ought to be met.
Once you have gotten your specifics taken care of, search the web for SEO reseller reviews. If the initial batch of results is a bit overwhelming, you can add a keyword or two to that query that describes your specific situation in order to narrow things down a bit further. Take a close look at what others in your situation have had to say about any reseller out there right now, and determine which of these options are the most consistently well reviewed by their clients. Contact each promising reseller in turn for written estimates on their plans and services, and choose the most comprehensive such professional in your price range for best results!