Why collecting money is the last thing you want to do:
First of all sites and museums that look abandoned are not so because of a shortage of public funds. They could have been purposefully left to deteriorate so that they may be looted. So money can’t help there. What can help is you raising awareness on the illegal antiquities market.
Very often the problem is not the money, but the system for hiring the personnel that will do the work and how through their involvement some wise guy- politician or other form of lowlife- will be able to drain public money. What you can do there is get in touch with the local organizations and individuals that are protesting the situation and help them gain visibility. They know very well what to do and how to do it, they only need moral backing. Visibility will make it harder for these people to be ignored or harassed in order to keep quiet.
Remember that fascist organizations are often involved in the vandalizing of such sites, so there is always the element of fear for locals.