I have recently launched a website which is using a free sitemap generator. It's a large travel agency site with predominantly dynamically generated content - users can add their products as and when and be listed automatically.
The guy doing the programming for the site says the sitemap generator is not up to the job and that I should be ranking far better for certain search terms than the site is now. He reckons it doesn't provide lastmod info and the sitemap should be submitted every time a new directory is added or change made.
He seems to think that I need to spend £400-£500 for him to custom build a site map. Surely there's a cheaper option out there for a sitemap that can be generated daily or 'ping' Google every-time an addition to the site is made or product added?
Sorry for the non tech speak - I've got my web designer telling one thing and the programmer another so I'm just left trawling through Q&As.