How much would this item cost

[Mistwell]

Yes I think if you keep the standard action portion, and everything works as if it is a first level spell cast by a first level wizard, then 8000 is in the ballpark for pricing. It might be a tad too cheap still, but I don't think it would break the game or anything.

 

[Infiniti2000]

Instead of just a plain +1 platemail, how bout something called Missileblocker, +1 platemail that lets you cast shield once per day.

Go for it, just be careful on the price, or not, as your gaming style dictates.

What about creating intelligent weapons, or those that existed back in the day.

There exist rules for intelligent weapons. What's the problem with them?

Other companies have said that this is perhaps not a good way to do it, and have made feats called craft single use item, craft continous item etc..

And fwiw I agree that the system is not the best it could. I redesigned it myself using other people's ideas and posted it in the House Rules forum. I'm guessing the post is gone, but if you want the Word doc, send me an e-mail. I have not playtested it yet or worked out bugs and it's incomplete (and responses were limited), but you're welcome to it. Some day I'll put it on my website.

 

[yipwyg]

The above item would cost

Full Plate 1,500
Masterwork 300
+1 Magic 1,000
Shield Use Activated, 1/day ((1 x 1 x 2,000) * 2) / 5 800

The total price of the armor would be 3,600 gp

Shield spell added to armor
Caster Level 1
Spell Level 1
Use Activated x 2,000
Minutes/Level Duration x 2
1/Day 5 / 1 = 5

 

[Lord Pendragon]

One problem with this approach is that you are breaking the "market modifier" rule used in weapons/armor.

Setting aside the pricing issues of the True Strike spell in particular, I'd probably price the 1/day spell effect as a slotless magic item, then add that cost as a flat +[gp value] to the cost of the armor.