New vehicle purchase vs keeping the old one dilemma

[Catica]

I have a 15 year old Prius with 250,000 miles.  The battery was replaced at 150,000.  I pay about $550 yearly insurance for the car.  The car is used mostly for pleasure but DH uses it for his construction business once in a while.  We had one thing fixed recently which cost us $300 (something related to emissions sensor). A year ago we replaced a water pump.  It hasn't given us any other issues recently.
I see that there is $4500 tax incentive on a new Prius, plus Toyota is offering $3500 cash back and $1500 state incentive.  I wouldn't have to finance the car.  I'm wondering if now is the time to upgrade.
I do understand the argument between buying new vs buying old, and I don't want to consider it at the moment. 
What do you guys think, is it worth it (provided one is willing to accept the loss associated with buying new vs buying old)?  I also realize that what's worth to one may not be worth to the another person.  I'm just hoping for some comments persuading me either staying with the current car vs getting a new one.

Thanks!

[zolotiyeruki]

So what's making you think you should get a new car?  Older cars need more repair than newer cars, as parts wear out, but it doesn't sound like your current car is giving you much trouble, so what would you gain with a new car?

[Catica]

So what's making you think you should get a new car?  Older cars need more repair than newer cars, as parts wear out, but it doesn't sound like your current car is giving you much trouble, so what would you gain with a new car?

The only thing that makes me think about it is that if in a year my car dies I will have to pay more for it because all these rebates won't be available.

[SunnyDays]

Can you save 9500 in a year?  Then IF your car dies, you won't need the incentives, and if it doesn't, then you're ahead.

[Catica]

Thanks.  I'm not going to buy it.  I can now eliminate this idea from my head.