No one can tell you how much your money is worth to you. I am a broke college kid with no money but tons of time to train, so ... money's worth a lot.

That said, weight doesn't make as big a difference as bike companies want you to believe. Very few tris are "hilly", so the weight is only a penalty if you repeatedly have to re-accelerate it. Is two pounds worth $500? That's a bit more than a full water bottle. Probably not right now, especially considering you could find those items on the secondhand market later if you decide you need them.

That said: All of these bikes are going to be awesome. Find one that you like, that speaks to you (ie, is really, really pretty) and you'll spend more time riding it.