is backup over WAN worth considering?

Provided my calculation of data transfer shows that it's "doable" within 3 hours everyday. I was considering this before I was presented with Symantec BE14. Now my partner is talking about 2 BE servers with dedupe on each side and other license options that would be required, not to mention hardware, etc. It's way over original budget and I'm not sure BE is really built for this. I mean, it's one thing if I raise the budget and the solution works, but quite another if it turns out to be an expensive pile of doodoo..