Frankly, most formatting you can do yourself. Hell, if you can figure out how to write your epic American novel on MS-Word, you can figure out how to save it as an HTML file and review that file through your web browser. From there, the distributors can convert your uploaded file to their specific format.
If you want to convert your files to MOBI or ePUB in order to sell from your own website (or just to check to make sure your formatting is correct), there's plenty of conversion programs out there. Some are free, others not. Among the ones out there are Aspose for Word and Calibre. I DO NOT RECOMMEND ANY PARTICULAR PROGRAM.
If you're a total technophobe, then by all means hire someone to do the formatting and conversion for you. But BEWARE!! There's a lot of scam artists looking to part you from your money. Make sure you get references. Personally, I think $400 to format and convert your manuscript file is a