Help pricing magic items for a Convention game

[Beholder Bob]

I'm writing an adventure and wanted to include some new items - and thought perhaps I should see the general consensus of Enworld as to the power level of these items. I wouldn't worry about it for my home game, but this is for a convention game, I want the item to be balanced to the general DnD public's view, not just my own. So, what do you think this would be worth/require:

Eldrich Quiver: 10 times a day, as a free action (via command word), an arrow drawn from the quiver is +1 for 1 round.

What would you charge, prerequisites, etc.?

I'll post some of the other items shortly...

BB

 

[Beholder Bob]

Hmm. If I remember correctly, magic weapon makes 50 missile weapons +1, while this item effects 10 missile weapons per day (1/5 the output). It is better in that they are not all at once, worse in that a group can not split it up. So, 2000*caster lv*spell lv*1/5 (1/day) = 400. The ability to use it when you need it, though, is worth a good boost, say 50%, so 600. This item has no slot, so x2, or 1200.

I was thinking 3rd lv caster, magic weapon spell prereq, and 1200 gp. On another board, it was suggested it was worth 5,500. I think I'll need to think upon the pricing further.

Oh, further items:

Fury of the Master (pair of silver rings) - 1 worn by the master, the other by the familiar - allows the master to sacrifice a spell as a swift action to increase the familiars attack and d4/spell lv damage. This may be done 2/day

Shadow Spike - when this cold iron spike is driven into a shadow, the object (or creature) the shadow belongs to is incapable of moving nor falling. Creatures are still able to defend themselves, they may not take any form of movement, though, and cannot be bull-rushed during this time unless ‘rusher’ makes a STR DC 30 check is made. Once this check is made, the shadow disperses, ending the effects. The shadow returns in d6 minutes. The spike takes 2 full rounds to drive into a shadow, provoking attacks of opportunity. The spike can be pulled free from a surface with a STR DC 15 check. Note: the spike can be placed anywhere along a creature's or object's shadow. A light spell (oth level or higher) cast on the creature or object ends the spikes effect.

Alchemical Retort - when a potion is placed inside it, the user places his mouth over the opening and exhales, losing exp equal to 1/3 the purchase price of the potion. This causes the potion to expand, increasing to 2 doses. This effect is permanent.

Goblin Rod - this rod is made of a deer's spine and skull, with eagle feathers and a wolfs tail at the bottom. It allows the wielder to spontaneously convert 2 spell levels or more to cast bless, doom, or bane.

Cowards bane cloak - this cloak causes all attacks against the wearer that ignore the wearer's dex AC to have a 10% miss chance, as the cloak rushes to obscure the wearer and misdirect the attacks.

Ring of potential - the ring acts as feather falling for up to a 60' fall - and after any fall of 5' or more, the ring is 'charged', losing its feather fall ability until the 'charge' is lost. While so charged, the wearer can add the distance fallen to their ground movement or jumps (to no more then double their normal value). Falling while the ring is charged has no effect (no feather fall), and once charged (5-60'), it can not be charged more - the only way to get 60' of 'charge' is to fall 60'.

BB