DPS5020-USB-BT, DPS3012, DPS5015-USB-BT, DPH3205.
Just check coupons out (with price alert and history). What is best price?
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. ($27.92): 2203ActiesNL
2. ($28.22): BG00c906
just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/i1u
Old coupons (from the oldest to the newest): BGRUMB15, BGAFF10OFF, BGCuponation10, 13f142, BGHONEY2110, BGd0b05d, 00c906, ADMITAD2212, 2022ACTIESNL, Terence, Tabby20, BG1efeb0, MVC8SPRING, 8BGwbg2204, 8wEbgaInS5, pROMo8cuPoN, BGJUNEGSG9, BG8ReviTrage, Cuponation9, 9OFFSUMMER, BG589b2e
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – RUIDENG DP And DPS Power Supply Housing [EU] ($-3)
Price history and price alert
Check out price history chart (for all/most countries) for RUIDENG DP And DPS Power Supply Housing. The lowest price was: $17.99.
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)).