Sorry to hear about your troubles. It might help if you added where you are located so people can better gauge what the shipping fees might be like.
Also, please note that your PowerMac G5 may be the fastest "air-cooled" model that Apple sold. I am fairly confident that it is not "passively cooled", however, which would imply that it has no fans whatsoever. In case you are not aware, there also do exist faster models without liquid cooling but these have been customized by owners post-sale and are hard to find.
