Upgrading charges-per-day items.

[Ambrus]

The Magic Item Compendium contains a slew of some nice items usable 3-times-per day. I'm interested in the possibility of upgrading some of them to ongoing continual-effect items IMC. The only thing left to do is figure out how much that would increase the items' price.

Looking at the Estimating Magic Item Gold Piece Values table in the DMG, the guideline for pricing charges-per-day items is to "Divide by (5 divided by charges per day)". So if I understand it correctly, as a base, a continuous-effect item would cost as much as an item with 5-charges-per-day. So upgrading a 3-charges-per-day item to a continuous-effect one is as simple as multiplying its price by 1.67? Similarly, upgrading a once-per-day item to a continuous-effect item is a matter of multiplying it's cost by 5? Am I following this correctly?

And yeah, I know the chart is just a suggested means of estimating magic item prices; I'm just trying to figure out a starting point.

 

[StreamOfTheSky]

No, the charges per day listing only works for up to 5 charges per day. Beyond that, the DMG assumes it may as well be one of the other categories. You'd want the use activated / continuous use listing, with a multiplier of 2000 gp. of course, that's only a guideline as you said, and if you're using MIC items, it'll probably result in overpriced items compared to the originals with limited use from MIC. Really depends. The heartseeker amulet that lets you make touch attacks...definitely worth DMG pricing guidelines if not utterly broken at unlimited use, for example.

EDIT: Oh, I thought you were building the price from scratch. I suppose doing the charges per day multiplication in reverse (inverted) would technically be right, but I don't think that would leave you with good prices. Almost all would be ridiculously cheap. And is this strictly for items with only one possible use? As ooposed to the ones that give you multiple abilities with different charge costs?
I really don't think using the table's a good idea at all. for example, the Boots of Swift Passage. Swift 5/day teleport for 20 ft. Using the table, it'd cost the same for unlimited use.
http://www.d20srd.org/srd/magicItems/creatingMagicItems.htm#tableEstimatingMagicItemGoldPieceValues