I wanted to jump in here really quick since I sell fabric on eBay. I have listed my longarm quilting services on ebay in the past but not for that cheap. My prices run more like the penny per square inch. I had more success with Etsy, but then found out that longarm quilting is not allowed. Which stinks, because I was getting good business quilting from Etsy. My original thought was to have an Etsy shop and not have to worry about a website too. But now it looks like I will be getting a website set up over the next week or two.
Ask lots of questions to make sure of what she is offering for the price, check her feedback and see if any of it pertains to her longarm quilting. Ask for pictures or a link to an online photo sharing site with her pics. And of course, somebody she has done work for in the past!