For my Halloween sale announcement this year so did I decide to dress up Roy as Kyubi from Yo-kai Watch.
And yes, he spent a lot of money for the costume parts and hair sprays. XP
About the sale, so is it 40% off as long as it's Halloween themed.
Which means that the character(s) have to be dressed up for the occasion. Or maybe your character is actually a vampire, werewolf, mummy, or other famous horror monsters, then that counts for the sale.
Día de los muertos (Day of the dead) also counts because I find that holiday interesting.
For more information, look for my commission info here: https://www.weasyl.com/%7Ecyborglucario/submissions/1495859/pricelist-2017
Roy Jackalland (c) Cyborg-Lucario
Yo-kai Watch (c) Level-5 games