I would absolutely buy this on DVD. It doesn't "tarnish" Batman at all. It is supposed to be campy and funny, and it succeeds. I like the new serious Batman movies a lot but if anything tarnishes Batman it is the campy un-funny Batman of Batman Forever and Batman and Robin. In retrospect even Time Burton's Batman really isn't that great. Adam Wests Batman however is hilarious.
Also I support the availability of virtually every show on DVD, if for nothing more than nostalgia.