A lot of unknowns here. What is the climate? What is the cost of
electricity? What is the deductibel the OP is out if he goes the
repair route?

I'd take a look at my electric bills during AC usage months. And I'd
look into possible rebates from the electric company. Many offer
rebates that go up with higher SEER units. If you can get $1000 from
the warranty, plus another $400 or so in additional rebate, tax
incentive, etc., and you use it a reasonable amount, I'd go with
replacement.