RD6012 RD6012W S-800-70V 11.4A Switching Power Supply (Banggood, Aliexpress: Size 241*125*65mm, Input voltage 90-132VAC/180-264VAC, Adjustable ±10%, Voltage 70V, Model S-800-70V (Custom Edition), Power 800W (the best price with coupon)).
Go down and check coupons out. Remember to check price history if it is available. Best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
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. ($76.50): hoNEYbGdeAlS
2. ($78.16): BG00c906
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): bGhOnEy10, BG70V, BGS70V, BgcLuBofErtA10, BG53PSU, BGCLUBOFERTA10, BGAFF10OFF, BGCuponation10, BG59PSU, BGHONEY2110, 13f142, BG4742c4, ADMITAD2212, Terence, Tabby20, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN
(these coupons are old, so probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for RD6012 RD6012W S-800-70V 11.4A Switching Power Supply. The lowest price was: $39.99.
Price records source(s): 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)).