State your offer for them. Try not to make it too low, like 4k for black roses. I wouldn't want the offer too high either, as I like giving items for a good price -- I am in desperate need for bells, but would like to give the items lower than they usually go for.
Hybrids
Pink Roses x6
Purple Roses x2
Pink Cosmos x2
Orange Roses
Orange Tulips
DLC
Rice-Plant Bed
Festival Lantern x2
Slushie Machine x2
Other Event Items
Skeleton Hood x2
Werewolf Hood x5
Ghost Mask x2
Monster Mask x2
Mummy Mask
Jack-In-The-Box
Blue Glow Wand
Ultra Scope
Misc.
Spooky Chair
Spooky Vanity
Spooky Wardrobe
Spooky Dresser x2
Spooky Clock
Spooky Sofa
Spooky Table
Spooky Wall
Spooky Carpet x2
Balloon Closet
Balloon Lamp
Balloon Dresser
Balloon Sofa
Balloon-Dog Lamp
Mush Bed
Mush Closet
Creepy Floor
Boxed Figurine
Harvest Dresser
Eiffel Tower
Fine Painting (Arearea, by Paul Gaugin. Legit)
Scary Painting (Otani Oniji II, by Tōshūsai Sharaku. Legit)
Warm Painting (The Clothed Maja, by Francisco Goya. Legit)
Hybrids
Pink Roses x6
Purple Roses x2
Pink Cosmos x2
Orange Roses
Orange Tulips
DLC
Rice-Plant Bed
Festival Lantern x2
Slushie Machine x2
Other Event Items
Skeleton Hood x2
Werewolf Hood x5
Ghost Mask x2
Monster Mask x2
Mummy Mask
Jack-In-The-Box
Blue Glow Wand
Ultra Scope
Misc.
Spooky Chair
Spooky Vanity
Spooky Wardrobe
Spooky Dresser x2
Spooky Clock
Spooky Sofa
Spooky Table
Spooky Wall
Spooky Carpet x2
Balloon Closet
Balloon Lamp
Balloon Dresser
Balloon Sofa
Balloon-Dog Lamp
Mush Bed
Mush Closet
Creepy Floor
Boxed Figurine
Harvest Dresser
Eiffel Tower
Fine Painting (Arearea, by Paul Gaugin. Legit)
Scary Painting (Otani Oniji II, by Tōshūsai Sharaku. Legit)
Warm Painting (The Clothed Maja, by Francisco Goya. Legit)
Last edited: