Wacker and Filarmonica: both are great shavers. It is a matter of personal preference whatever you will like most.
Wackers are current production, Filies are no longer made and therefore part of their price is collectors' value. Same applies to other vintage 7/8 or 8/8 razors. Few were made at the time as most shavers used to prefer 5/8 or 6/8. Bigger is better seems to be the current trend.