Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. There is one great coupon!
Link: Banggood product page
Coupon (45.72 USD): BGc7b765
(CouponsFromChina.com tip: coupon code has to be applied in shop’s cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): e2bcea, 502C6B, toys12, BGcos584, 0e7f33, BGHAO1, FBCOUPON1, BGCOU07, BgcLuBofErtA10, BGAFF10OFF, BGCuponation10, 13f142, BGHONEY2110, BANGGOODSD
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for Inflatable Pick up Alien Costume.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).