Before I start, let me say that "by the book", you first look for a similiar item and price it by that. I'm assuming there is none.
Let's start with
Delay Death, a 4th level cleric spell (I know other versions have it as 3rd level, but the SpC is the latest printing and so takes precedence).
If you look at DMG, p285, chart 7-33, under "Spell Effect", you see
Spell Effect Base Price Example
Single use, spell completion Spell level × caster level × 25 gp Scroll of haste
Single use, use-activated Spell level × caster level × 50 gp Potion of cure light wounds
50 charges, spell trigger Spell level × caster level × 750 gp Wand of fireball
Command word Spell level × caster level × 1,800 gp Cape of the mountebank
Use-activated or continuous Spell level × caster level × 2,000 gp2 Lantern of revealing
A 4th level spell requires a 7th level caster, so
Base Price = Spell level x Caster level x 1800gp
= 4 x 7 x 1800gp
= 50,400gp
You said 3/day, and the chart has
Special Base Price Adjustment Example
Charges per day Divide by (5 divided by charges per day) Boots of teleportation
Base Price = 50,400gp / (5 / charges)
= 50,400gp / (5 / 3)
= 50,400gp * (3/5)
= 30,240gp
So an amulet of Delay Death usable 3/day at 7th level costs 30,240gp (market price)
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Sadism]http://dndtools.eu/spells/book-of-vile-darkness--37/sadism--169/]Sadism is a 2nd level spell which requires a 3rd level caster. I'm not sure, but I think usually everything in magic item has to be at the same caster level, so we'll up it to caster level 7 to match Delay Death.
Price = Spell Level x Caster Level x 1800gp / (5 / charges per day)
= 2 x 7 x 1800gp / ( 5 / 3)
= 15,120gp
Ditto for masochism, price = 15,120gp
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Those are the prices for 3 different amulets, but you want them all as 1 amulet. So look at DMG, p282, sidebar
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 (such as a ring or a necklace),
each additional power not only has no discount but instead has a 50%
increase in price. A belt of Strength +4 and Dexterity +4 is more valuable
than a belt of Strength worn with gauntlets of Dexterity, since it takes up
only one space on a character’s body.
Note that chart 7-33 also has the line
Multiple different abilities Multiply higher item cost by 2
but errata changes this to multiply the lower item cost by 1.5, and so with that update it agrees with the sidebar above.
Cost of amulet = Highest Cost + (1.5 x Lower cost) + (1.5 x Lower cost)
= 30,240gp + (1.5 x 15,120gp) + (1.5 x 15,120gp)
= 75,600gp
That's if you want to buy it. If you make it, it costs half that and takes 1 day per 1000gp
Cost to create = (75,600gp / 2 ) = 37,800gp
Days to create = (75,600 / 1000) rounded up = 76 days
Good luck!
