Hello,
because there is the possibility to import and export products?
CSV or EXCEL?
Google translation.
Use the third party tool, CSV Improved, now at CSVI 4.0 beta 2 - to work with Joomla 1.7 with VirtueMart 2 - will be completed soon. http://www.csvimproved.com/
This has been the importer / exporter of choice for many years now.
CSVI is a great product but any other idea if I don't have PHP 5.3 installed on the host?
Change hosts is the logical response. PHP 5.2 is too old now, and VM2 and Joomla 2.5 really need PHP5.3+
PHP6 is already out and being installed by some hosts....
You could look at this thread, but I don't know how good this is or if it works with old PHP versions. http://forum.virtuemart.net/index.php?topic=93762.0