How much does Will-o’-Wisp cost?

Base price 80; in the shop 89 at wave 1, 170 at wave 10 and 260 at wave 20 (before price modifiers).

How do you unlock Will-o’-Wisp?

It is unlocked by the challenge “Smells like something’s burning? ” (Kill 30 enemies by burning them in a single wave).

Tier III item · Base game

Will-o’-Wisp

Will-o’-Wisp is a Tier III item in Brotato 1.1.15.4 (Base game). Effects: +1 Elemental Damage for every 30 burning enemies you kill during a wave (max +4 per wave). -7 % Attack Speed. It has a base price of 80 materials: 89 in the wave 1 shop and 260 by wave 20. There is no limit on how many you can hold.

This section as JSON: /raw/items.json

Quick answers (3)

What does Will-o’-Wisp do in Brotato?: +1 Elemental Damage for every 30 burning enemies you kill during a wave (max +4 per wave). -7 % Attack Speed.
How much does Will-o’-Wisp cost?: Base price 80; in the shop 89 at wave 1, 170 at wave 10 and 260 at wave 20 (before price modifiers).
How do you unlock Will-o’-Wisp?: It is unlocked by the challenge “Smells like something’s burning? ” (Kill 30 enemies by burning them in a single wave).

Effects

+1 Elemental Damage for every 30 burning enemies you kill during a wave (max +4 per wave)
-7 % Attack Speed

As the game prints them in the shop, for a character with no other stats.

Base price

Limit

None

Tier: Tier III
In the shop: Yes
Unlock: Smells like something’s burning?
Game ID: item_will_o_the_wisp

Tags (what characters' shop preferences look for)

Elemental Damage

Price by wave

Wave	1	5	10	15	20
Shop price	89	125	170	215	260
Recycle for	22	31	42	53	65

How this is worked out

Shop price = (base + wave + base × wave × 0.1), rounded down, before price modifiers (an items-price stat changes it by its percentage). Recycling returns 25% of that. From the game's ItemService.get_value and get_recycling_value.