Redevelop Existing Website Onto Magento

Hi, we currently have an ecommerce site set up and hosted with EKMPowershop.
Unfortunately, EKM is not easy at all to link an EPOS system to, with only a couple of companies wanting a huge price to do this.
However, we have found a reasonable company whom can supply a decent priced EPOS solution and integration, but to a Magento site.
Therefore, in essence, we are after a rough price to redesign our current site onto a Magento platform or Magento Go, and to provide necessary training for the upkeep of adding products etc.

Current site is www.fudgydoocountrystyle.co.uk.

If you can help, and have any ideas price wise, would be extremely grateful to hear from you.
Regards
James