To build or to buy; need some help on several fronts starting with web CMS
I am trying to setup some websites that I am getting paid for and I am having trouble finding exactly what I want, there just are too many options and none of them that I have read about on google seem to be exactly what I need. I would like to know peoples experience/opinion on whether or not it is going to be better to build or buy something that does the following (and if it is to buy please tell me which):
I need a website that will allow my non-technical customer to cross list items on eBay and/or Amazon and/or other, while also posting on their site. They are a small thrift store non-profit that helps women in need by giving them a place to live, a job (not always at their store), education, and other support. They are very worried about not being able to make it work as the thrift store is a new addition to their operation and so far they are not making money.
I have looked into several wordpress plugins but really don't know for sure that they will be exactly what I need, suggestions would be nice. I have an idea that I could make a site to do all of these things but I know it will take more time and money than they can afford, so I would need to sell or offer it to other customers, and I am worried about maintaining such a project as I am an employee of one at this point.
Any guidance is appreciated.