Hi!
I'm ready to get cracking on your Unity 3D scene with pathfinding. Actually, it'll be a scene, but also as per your request in the details, you'll really be getting a character controller, with an isometric (non-rotating) camera, which walks to your desired destination, after you direct the "box" character by point-and-click movement, with the mouse.
To be really honest, I was rather shocked at the steep price of the bids for this request. Honestly though, after working with Unity3D, I understand your need for this type of controller, but NO ONE should be charging as much for this feature to be custom-built for you, like the other bidders are.
Sorry for the rant. I'm ready to begin work on this feature and let you test it out. (I hope you'll allow the testing to be on a remote machine of mine, (Actually run through the web player for unity, from a website of mine so you can see it works, without me giving it to you for free.) ;0 (Hope you understand. )
Enjoy your day! Let me know if I can create this feature for you! Happy Game Building!
P.S. (Note: My bid's "Deliver In: time" assumes that you'll want to test/tweak some things too.)