Nikon Lens Rebates and the D600

Hi Everyone,

I'm hoping I can get some advice from the forum.  I'm currently the proud owner of a D600 and absolutely love it!!  I should also say I've got an 8 month old baby that I take a ton of photos of.  I'm currently using a 60mm F2.8 and 50mm F1.8.  I've been waiting to make a big purchase on Lenses and with the current rebates it seems like a good time.

I've looking at spending about $3000 - $4000.

I've sold on getting the 70-200 for the currently price, so that is $2100 out of the budget.

I was looking at the Nikon 24-70 and I came across the Tamron 24-70.  The Tamron 24-70 is about $400 cheaper even with the rebates.  I'd love to save $400 but I don't want to kick myself later on.

I was also looking at the Nikon 28-300 and was pleasantly surprised by the sharpness!

Thanks for all your help!!