Bashing Shields, what else modifies them?

[Seannoss]

To my knowledge or best guess, all bashing does is upgrade the base damage and allow a +1 enhancement bonus to attack and damage. I know there is an archtype that enhances this.
But does material matter, like cold iron? Or not because that would be more on shield spikes and not the shield. Could you craft a bashing, holy shield? No, because holy is not a shield enchantment?
I'm curious about any or all possibilities as this is for a WoTR campaign, so about anything is fair game.

[Dark Immortal]

Quick response before I go to bed: a spiked shield is enchanted like any other shield, so holy property does not count and enhancements on the shield don't count toward regular shield bash attempts in any way.

However, a spiked shield can be enchanted as a weapon in it's own right.

I believe this means that you can enchant it separately as both a weapon and a shield. So a +2 defending/+3 keen, flaming burst spiked shield.

[KainPen]

yes it has to be enchanted separately like a double weapon has to be one enchantment for armor and one for the weapon properties. Being made of a special marital only really serves no dual purpose of armor and weapon with the expectation of mithral, that I can think of which can be used to go through Silver Dr and effects weight and reduce armor check penalty.

Shield master feats lets you double dip with enhancement bonus letting it working for armor and a weapon effects. This is why many say it is over powered and broken, it lets you get +5 weapon at half cost as well as full +5 piece of armor at normal cost.

[Bizbag]

There is debate over exactly how to price the resulting item, but a +1 defending, +1 holy shield is possible. A heavy version would deal 1d8+1 + 2d6 vs evil.

[blackbloodtroll]

For pricing, it is identical to enchanting a suit of armor with armor spikes.

You enchant one, or the other, and neither has any effect on the price of the other.