I've been playing violin for nigh on 17 years now. There's no such thing as an easy instrument, they all have their challenges. First thing is that moving from a fretted instrument to a violin could be a real shock to the system, intonation is much more crucial then when you have a goodly space between frets to aim for ;)
The other thing that I would say, and this is no slight on the guitar so please don't take it as such, is that the violin is much less forgiving of "sloppy" technique than you can get away with on the guitar. *waits for the flaming to begin*
And yes, all the rumours of spending the first few years sounding like something inappropriate is being done to neighbourhood pets? They're all true. But it's worth it, because one day it clicks and sounds beautiful. I certainly wouldn't have wanted to learn anything else for my first instrument. And it does mean you can then cross over to mandolin at somepoint too :)
My best suggestion is get hold of a decent teacher in your area. A lot of them have cheap instruments you can borrow to practise on between initial lessons. Otherwise most music stores carry cheapo violins for under £100.
If you need any advise or comments then PM me :)
*Rahnooo*