$9.99 – QC3.0 USB Output: 4.5V/5A /5V/4.5A /9V/3A /12V/2.5A max, LED light color: Blue /Red /Green(optional), Product material: ABS, Size: 5.4X3.7X2.9 cm, Product Color: Black, input Voltage: DC 12V-24V, Type C PD Output: 5V/3A /9V/3A /12V/2.5A /15V/2A /20V/1.5A max.
$9.99 – that is current price with coupon for 12-24V 48W Dual USB Car Charger (in Banggood). Just check coupons out (with price alert and history). Best price?
Latest coupon code price check (UTC time):
Banggood ($9.99)
Banggood warehouse is located in China. So I have checked for active coupons (all category coupons and old ones), but there was no working coupon in Banggood. Well, is it a good price anyway? Good price! It’s lower than average one ($10.49)!
Link: Banggood product page
Price: $9.99
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG253d88, BGCarEle4, BG421c45, BGb3bdda, BG5549c0, BG997246, BGGRJAN2901, BGCarEle5, BGc9787e, BGLMQ15, BGSCM11, BGAMMT03
(probably won’t work, but you can try them out)
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.
Price history and price alert
Check out price history chart (for all/most countries) for 12-24V 48W Dual USB Car Charger. The lowest price was: $7.99.
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)).