$69.34 – UNI-T Digital Megohmmeter UT502C 2500V Insulation Resistance Tester Ommeter Megometer Ground Meter Backlight Auto Range.
According to my DB the lowest price is $69.34 for UNI-T UT502C Megohmmeter (in Banggood). Price history, coupons and price alert are available on this page. Let’s see what best price is ATM.
Latest coupon code price check (UTC time):
Banggood ($69.34)
Banggood warehouse is located in China. There is no active coupon in my database right now (for Banggood). Low/high price? From what I can see this price is higher than average price ($64.75).
Link: Banggood product page
Price: $69.34
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGM1TOOLS88, BG20236Tool, BGTOOS729, BG8FORMULAMX, BGCOUPERTBF8
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
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 UNI-T UT502C Megohmmeter. The lowest price was: $62.04.
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)).