@horacio your problem is not unique - there is an maintenance cost involved in using any software application, esp. nowadays that the pace of change is crazy. Your choices basically boil down to: a) not upgrading and staying on old, unsupported version forever, b) try to minimize the customization of the platform when you set it up, so that upgrades are less painful, and c) pay another company to upgrade your pltaform. At least with open source, you generally get to choose the vendor for option C - with propietary and saas you are pretty much locked in...