Multiple abilities on a magic item

[Florian]

IThis one does give a discount for more abilities for the less valuable (since I assume they mean less costly/expensive), but it only applies to slotless items. I can't find any real explanation of what qualifies as similar--does it need to be a bonus to the same stat (e.g. a luck and deflection bonus to AC)?

You can use staves as an example item for this.