Joomla - updating from v1.0

A friend has an ecommerce site based on Joomla 1.0 and Virtuemart. His developer is quoting £2500 for upgrading to Joomla 2.5, which seems very expensive to me, but I have little knowledge of Joomla.

Is the upgrade path as tricky as the price suggests?

Upgrading to joomla 2.5 doesn’t cost much, but the real task is integrating virtuemart in the ecommerce site. But still your developer is asking for too much. Hence you can try searching for some other reliable and affordable joomla service provider who can do this task for you. <snip/>

There is no direct migration from Joomla 1.0 to Joomla 2.5.You must upgrade from 1.0 to 1.5 and then from 1.5 to 2.5. All the detailed instruction are published on Joomla documentation. You should have a look at these tutorials firstly and then consider you can do it yourself or hire some one.

Migrate from Joomla 1.0 to Joomla 1.5:
Migrate from Joomla 1.5 to Joomla 2.5: