I've used the 'build a site' tools on a few services (iPower.com and Heart Internet spring to mind, along with the free Google Sites) but have not been developing many sites for clients of late (and therefore have continued to use some HTML coding by hand, and methods many 'web designers' might look down on).
The type of business could be important to how best to develop a site - some use content management systems (CMS) to allow the business to update the site themself, adding 'news' pages, etc {it means the end user is responsible for spell checking, and timely uploading / removal - eg if there was a special offer on for just a week or two}, while other developers lock the client into paying 35 quid an hour or part hour for alterations, and all alterations have to be done by the site developer. The latter can be a rip-off / scam, as are instances where the domain name registration does not show the client, but has the website firm as the 'owner' {meaning they can hold the client to ransom, because the client cannot legally demand a transfer of the domain and don't control the domain, so the development firm one saying 'This is the site of XYZ Ltd but is offline as they owe money'}.
Sorry for rambling a bit - I did prepare several pages about 'gotchas' when getting a web site built for small businesses, mainly saying what bits to keep control over and never release to the web site developers! (I still have the domain for that help guide, but moved only client sites to a new {UK-based} hosting firm before I was in hospital, and I've yet to put at least half my sites back online).
So, is the firm wanting to do e-commerce, or just an online glossy about their services / products ?