Is there a way to calculate the cost of a spell-completion or spell-trigger item with uses-per-day? The charges per day section seems to only really suit command word items. Spell completion only seems to appear in its single-use entry, which would actually be cheaper as a single use per day, which would be completely backwards.
With respect to continuous use items and xp penalties they are assumed to have 100 charges. One can assume that a 50 charge item is therefore half the value of the equivalent continuous use item, so doubling the value to spell level x caster level x 1500 / (5 / uses per day) should be fitting for a spell-trigger uses-per-day item.
Single use spell completion is half the price of single-use use-activated(which still requires its own standard action...) and listed again with continuous at 2000gp. If it is again half-price then spell completion per day would be calculated using spell level x caster level x 1000 / (5 / uses per day)
Speaking of which, command word really doesn't seem to make sense without uses per day. The example item is based upon uses per day, and if one assumes that just omitting the limitations would result in unlimited use for the same cost as five uses per day. Although unlimited use without activation is just 200gp more so I guess that 5 charges per day is regarded as not being appreciably different from unlimited use anyway...
P.S.
Multiple different abilities Multiply lower item cost by 1.5 Helm of brilliance
Burning hands is similar to scorching ray
Multiple Similar Abilities
For items with multiple similar abilities that don’t take up space on a character’s body use the following formula: Calculate the price of the single most costly ability, then add 75% of the value of the next most costly ability, plus one-half the value of any other abilities.
Gauntlets are probably not considered taking up a slot on the body, but it is difficult to say, I am pretty sure that they don't appear on the list of item slots and that they can be worn under a weapon or shield. If you wanted bracers on the other hand, then clearly this rule does not apply...
Multiple Different Abilities
Abilities such as an attack roll bonus or saving throw bonus and a spell-like function are not similar, and their values are simply added together to determine the cost. For items that do take up a space on a character’s body each additional power not only has no discount but instead has a 50% increase in price.
Once again, the effects are not similar.
You get a discount for slotted items, and cramming more into that discount would probably cost more than using unslotted items, which you could just make multiple items of instead. If I had to guess I would say that different abilities is just a term and not separating the item from 'similar abilities', so pay full price for the first ability, and 1.5 for later abilities, unless ithe item is unslotted AND the abilities are similar, in which case you use to 100%, 75%, 50%, 50% model...