What is the cost of Stone of Good Luck/ 5e Luck Stone in dnd?

Stone of Good Luck ( 5e Luck stone) is typically a rough polished agate or related mineral. Its possessor gains a +1 luck bonus on ability checks, saving throws, skill checks & faint evocation; The Cost Price of the 5e Luck stone is 20,000 gp.

Does 5e Luck stone (Stone of Good Luck 5e ) need attunement?

As per Basic Rules, pg. 205, it is a Wondrous Item, uncommon and always requires attunement. While this polished agate is on your person, you gain a +1 bonus to ability checks and saving throws.

Notes:

Bonus: Saving Throws,
Bonus: Ability Checks,

Bonus: Initiative, Buff

Does the stone of good luck affect Initiative?

Skill checks are ability checks that you may add your proficiency to. It also applies to Initiative and spells like counterspell or dispel magic. There are usually four types of d20 rolls in 5e:

Ability Checks,

Saving Throws,
Attack Rolls,
Miscellaneous (everything else).

The Stone of Good Luck ( Luch stone 5e) bonus the first two includes death saving throws. It is because they are saving throws and Initiative. After all, it is a dexterity ability check. It also supplies its bonus to passive ability checks, mostly like passive Wisdom (Perception), because they are ability checks.

How is Stone of Ill Luck in 5e dnd different from the stone of good Luck?

The Stone of Ill luck 5e comes from Tales from the Yawning Portal, whereas the stone of Good Luck is from Basic Rules.

The 5e Ill luck stone is a Wondrous item, uncommon (requires attunement)

This polished agate appears to be a Stone of Good Luck to anyone who tries to identify it. It confers that item’s property while on your person.

Curse. This item is cursed. While it is on your person, you take a -2 penalty to ability checks and saving throws. The DM secretly applies this penalty until the curse gets discovered, assuming you add the item’s bonus. You are unwilling to part with the stone until the curse breaks with remove curse or similar magic.

What is the total bonus from the stone of ill Luck?

There are two options to add bonuses. Let us see which is more practical.

The stone of ill Luck adds a +1 to applicable rolls and subtracts two for a total change of -1 to appropriate rolls. The DM would need to remove two from relevant rolls in secret since they would be assumed to add the original +1 themselves.

The stone of ill Luck only appears to be a stone of Good Luck. It does not add the original +1, only subtracting two from applicable rolls for a total change of -2 to useful rolls. The DM would need to remove 3 in secret, 2 for the curse and 1 for the incorrect bonus.

Option 1 is easier to run and is friendlier to the players. Still, I can also see an argument that the stone appears to add the +1 while not adding anything.

The net result is -1.

Let us read the full description of the Stone of Ill Luck. It says, “it confers [the stone of good luck]’s property while on your person”, so we know that it does present the bonus of +1. That is your real bonus.

The item goes on to declare, “the DM secretly applies this penalty, assuming you are adding the item’s bonus.” It means that the DM will choose two from the player’s roll. You may interpret that the player is adding the item’s bonus. There isn’t anything to say you should first remove the 5e Luck Stone’s bonus.