Material: plastic, Ra: 80, Input voltage: AC220V 50-60HZ, Size: 88x45mm(H*D), Light color: white, Socket type: E27, Color temp: 6500K, Luminous flux: 500LM, Power: 5W.
Basically copy coupon, view price history or create e-mail price alert. Let’s see what best price is ATM.
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($4.63): BGAFF10OFF
2. ($4.63): BgcLuBofErtA10
apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): TTxBG10, BGXMABLB, AFfbG10, affbg10, 502C6B, BGBFCR01, BGBFAFF2019, BGCITYADS2019, BGVDay10%off, BGLIGHT2020, bGhOnEy10, BGdragonBoat, BGSS10%SW, BGLIGHT0920, BgoFErTaSchInA10, BGELIG0920
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Price history (for all/most countries) for Xiaomi Zhirui E27 5W 500lm LED Bulb is here. The lowest price was: $3.09.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).