Definitely worth it if you can afford another saddle. Like others have said, you can find really nice used western saddles if you look in the right place. If you trail ride a good amount it is nice to have a western saddle for the added comfort and extra security. I am a western rider and will occasionally ride english for fun. But I don't actually have my own english saddle because I know then I will be stuck riding with it on our trails. Not a bad thing, but with my gelding it surely doesn't extend my life expectancy. XD
I've ridden western all my life and probably always will, but my horse has shown a desire to jump and I may get me an English saddle at some point just for that. Hmmm.....wonder if I can graft western fenders and stirrups onto it? I'm not givin' up my blue jeans either....