I've spent entirely too much time and...well...cash, to not weigh in on this one.
I've tried a whole host of "affordable" mics for backup or for VO on the road...and I can say this now, and mean it.
Save your pennies, and buy the mic you like. If you use a 416 at home, don't settle for anything else.
Just save up, and get another one...or get one from ebay.
I have tried an Earthworks mic, I've tried the Rode NTG-2, I've tried an Audio Technica shotgun...
And I finally realized, that if I want something to be a backup for the 416, I should...just...get another 416.
It's hard to justify spending another $1K on the exact same mic you already own, but honestly...you'll be better off.
I'm getting another one this year. After I finish selling off all my excess mics that I've spent too much time and money on to try and "get an affordable" backup for my 416.
If you don't mind tweaking alot of sounds, you could get a different mic, but it's going to sound completely different than what you, or your clients, are used to.
But at this point, for my money, I'm going to just get another 416, to avoid being caught with my pants down if my only 416 ( which has already been rebuilt once ) takes a dive.
Good luck!
Oh, and if you find a place that has 'em for a good deal, please, let me know!
Thanks!
Mike Bratton
Voice Guy
www.mikebrattonvoice.com