Deal of the moment: $39.59 using a promo code (in Banggood). 12V Electric Scavenge Suction Transfer Change Pump Oil Transfer Pump 1-4L/min Motor Oil Diesel Extractor Pump For Car – Blue.
Updated:
Banggood
Warehouse in China.
Link: 12V Electric Scavenge Suction Transfer Change Pump Oil 1-4L/min
Regular price: $41.6
$39.59 with coupon: BGGDPWRTLS
Additional Banggood coupons:
1. First page
2. Second page
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
Here is price history (for all/most countries) for 12V Electric Scavenge Suction Transfer Change Pump Oil 1-4L/min. The lowest price was: $39.59.
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)).