If they're willing to invest a little in training, I'd say OpenERP is a fine solution. There's no recurrent licensing to pay and it runs just fine on any decent computer. As long as they don't need custom development or third-party modules, they shouldn't even need much technical support.

I've looked for training here in Romania, I couldn't find anything clear on the topic: what is provided and for what price.

I don't know if OpenERP S.A. has an office in Romania, but their Romanian partners will probably be glad to help you: http://v6.openerp.com/ed-classified/tid/97

I've already checked them: * http://www.erpsystems.ro/ -> this is a demo * http://www.apersis.ro/openerp.html -> under construction * http://www.openerpsaas.com/en/package-details (from Elastoffice) -> it's not very clear to me if they provide training * http://www.openerp-romania.ro/ -> just a "contact us" form * http://www.intellisys.ro -> couldn't find anything about OpenERP

Not to be snarky but the E is for enterprise. The overhead of learning and using the software versus the value delivered is not there for your typical mom and pop shop

Yes, you're right, I meant something simple to use for a small company.