Aliexpress
Click here… to search for Deerma VC50 Upright Vacuum Cleaner on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (157.72 USD): BGHOMEA13
Coupon (172.29 USD): 7bcdf9
(CouponsFromChina.com tip: apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Old coupons (from the oldest to the newest): 502C6B, 427168, 711d40, Dmvcgizit, BGDER15, PICODICOM, BGDEER05, aff7off, BGVC50, BGDRVC50, bgchinafest, bGpAnDacHeCk, BGHOMEAPP, BGAFF7OFF, BGHCLE15, bgshOOp10, BGHome15%, BGHOMEAPP13
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for Deerma VC50 Upright Vacuum Cleaner.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).