Whether you think it's wrong or not is irrelevant, your calculations haven't included all applicable factors and that's that.
With regards to what you think it's worth (completely different thing from your attempt at currency conversion) as I've already pointed out is subjective.
If you don't think it's worth it then don't buy it, if you do then do. That's your call, I can assure you nobody actually cares what you do or don't do with [b]your[/b] money