ATM you can buy Brake Fluid for 23.39 USD (in Banggood). Go down and check coupons out. Remember to check price history if it is available. What is best price?
Latest coupon code price check (UTC time):
Banggood (23.39 USD)
Banggood warehouse is located in China. Is it good price? This price is higher than average price (19.66 USD) for this item. Well, there is one coupon available right now.
Link: Banggood product page
Price without coupon: 25.99 USD
Coupon (23.39 USD): BGAMMT03
(CouponsFromChina.com tip: this code has to be applied in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGf475ef, BGSCM75, BGf6b5cc, BGSCM11, BG6aefd2, BGCRT313
(I don’t think these’re gonna work, but you can try ’em out anyway)
Aliexpress
Click here… to search for 12V Auto Brake Fluid Tester on Aliexpress
Here are coupons that you can use.
Price history and price alert
Do you need price history chart (for all/most countries) for 12V Auto Brake Fluid Tester? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).