$14.99 – Heart Core, Rivet, Conversion Head Accessories, Electric Rivet Gun, Rivet Gun, Rivet Machine.
According to my DB the lowest price is $14.99 for Electric Rivet Machine Conversion Head (in Banggood). Just check coupons out (with price alert and history). Do you want to know what the best price is?
Latest coupon code price check (UTC time):
Banggood ($14.99)
Banggood warehouse is located in China. Too bad there’s no coupon right now in Banggood. Low/high price? This price is higher than average price ($12.49) for this item.
Link: Banggood product page
Price: $14.99
Additional Banggood coupons: first page and 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
Check out price history chart (for all/most countries) for Electric Rivet Machine Conversion Head. The lowest price was: $11.99.
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)).