Project standard sync with sharepoint 2010

There is an option to sync project to SharePoint 2010 in Project professional.

However, there is no such option with project standard.

Could you please let me know two things here:

what is the price difference of  project professional 2010 with project standard 2010.

and secondly is threre a workaround if we want to sync project standard with sharepoint 2010.

tnx