Armor enhancement question

[GoldEdition42]

I currently have a +1 Breastplate but I wish to upgrade to a Defiant Breastplate (vs. giants).

Can I have it "added" onto my +1 Breastplate and what will this cost? 3,000 gp extra as I am already starting at the 1,000 gp cost for a +1 magical armor? Or 4,000 gp as this cost is set?

Perhaps I'll just get a Defiant armor right off the bat on a new set (so 1,000 gp cost) and a ring of protection +1 (2,000 gp) if that is cheaper.

Advice?

[Orfamay Quest]

Defiant is a +1 ability, so a defiant +1 breastplate is a +2 equivalent breastplate, costing 4000 and change.

Your current breastplate costs 1000 and change.

So it costs 3000 to upgrade.

You can't buy the defiant property on a piece of armor without an enhancement bonus of at least +1, so this is also as cheap as you can get it.

[Nefreet]

Armor and weapons must have a +1 bonus before being enchanted further, so you could not get Defiant for just 1000gp. You must pay the difference between the 1000gp you've already paid for +1 and the 4000gp to make it +2 (so, 3000gp).

[GoldEdition42]

Thanks for the quick replies. 3,000 gp sounds like a fair deal.