Howdy Folks --
FYI -- Updated ruling on multiple enchantments in slotted items....
Here's the way putting multiple enchantments into the same slotted item will work in Drakara: The final market price of the item will be the sum of the market prices of the 'parts', x 1.5. This results in a 'reasonable' price, which for two 'parts' that have the same price, amounts to spending double for the second one -- but which doesn't rely on the order of enchantment, doesn't change depending on what is added or increased in power when, etc. To further enhance a given item, figure out the new price, subtract the old price, and the difference in price is the amount of extra enchantment needed...
For example, a Cloak of CHA (+2) costs 4000, a Cloak of Resistance +1 costs 1000. Put together in a single cloak, the price will be (4000 + 1000) x 1.5 = 7500. Later, the owner decides to get its Resistance enchanted up to +2, normally a 4000 cost. The new price would by (4000 + 4000) x 1.5 = 12,000 -- so the market price has gone up by 4500, it will take the enchanter 4 and a half days and cost him 4500 / 2 = 2250 in materials and 4500 / 25 = 180 xp. The owner decides, that isn't good enough, lets go for Resistance +3 instead of +2. The new price would be (4000 + 9000) x 1.5 = 19,500 -- so the market price would be 12,000 greater than the original CHA+2/Res+1 cloak, taking the enchanter 12 days, 6000 in materials and 480 xp. The owner says, yeah, I can afford that -- then a month or so later, comes back, now wants CHA boosted from +2 to +4. New price is (16,000 + 9000) x 1.5 = 37,500, or 18,000 greater than the CHA+2/Res+3, 18 days of time, 9000 in materials, and 720 xp. And so on and so forth.
This rule will prevent wanton addition of small-value add-ons to a high-value initial item -- but it does allow a combination of effects to be located within a single item on a consistent basis, and the closer in value the enchantments are, the closer it is to the 'second enchantment costs double' idea. It may, amazingly enough, also be what at least one of the writers originally intended...but even if not so, it is the way it will work in Drakara.
If an item doesn't take up a slot, extra powers just cost normal. Some special rules may apply to powers that cross standard item categories -- for example, Health is a Wondrous Item feature, adding it to magical Dastana might be possible as bracers and dastana use the same slot, but the Dastana would be required to be magical to start with, cannot simply put Wondrous Item effects into mundane Dastana, because in general for Armor, must have at least a +1 enhancement before any enchantments can be added. Also, working on cross-category items will require both appropriate item creation feats be involved, as for example adding Health to Dastana would require Craft Wondrous Item to add the Health feature and Craft Magic Arms and Armor to enable the Dastana to accept the enchantment.
Note, however, that for multi-purpose slotted items, special ordered, the actual cost of the specific features, rather than the final market price, will determine what can be crafted in Marike -- i.e. if an item crafter such as Soshi Ashiko can make items of CHA +2 (4000) and Resistance +2 (4000) then that caster can spend extra time and materials to combine them both into a single item costing 12,000.
I hope that clarifies how things will work from here on, so that for future purposes characters know what they can get added to their existing stuff... :)