Ok I been looking online for formulas on making magical items but cant find what I am looking for. I have a few guess's but still not sure how it goes. Below is a list of what I am looking to do so if you can help me out I would be very greatful.
Nightstick-
the cost is 7500 for 4 extra turnings, the only think I can think of that would be in the rules is then 'Charges per day' which is divided by 5 for each charge. So were is the base price coming form and how it became that price? because I would like to add this effect on other items like a swords instead on a rod if I can, just not sure how you do it with turnings.
Feats-
On another post I've asked a simaler question and will use that for a base for this question. Feats don't have a caster level or a spell level so I don't know what it would cost to put a feat effect into an item. Two in mind are lord of uttercold and energy substation, they are metamagic but have 0 level cost, to my guessing on how to add them in is the 'use-activated or continuous' section which would cost 2000 for each feat. Is that right or have I forgot to add something?
Most magic items that grant feats cost about 8,000gp market price. And you can look at a Nightstick as granting the Extra Turning feat. There is no specific formula for each, so reverse engineering is all we have. But they were quite consistent about the 8k per feat. (Horizon Goggles, Gloves of the Balanced Hand, Nightstick, even the Dark Blue Rhomboid Ioun falls in range with the markup for being slotless. The Fanged Ring is
stupidly cheap on the other hand.) To add an effect to another item the Magic Item Compendium went with a +50% surcharge.
So 12,000gp market price to tack on a feat (or 4 extra turn attempts) to another item. Though as a DM, letting people add feats to items willy nilly might call for an escalating price for each feat beyond the first, much like enhancement bonuses scale up.