Just check coupons out (with price alert and history). What is the best price?
TS-B2 TIP, Temperature Adjustment Built-in STM32 Chip for Electronic Worker / Engineer etc.
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($38.88): BGTS100
2. ($47.27): BGTool15
3. ($50.05): BGAFF10OFF
4. ($50.05): BgcLuBofErtA10
5. ($50.61): 7d18f7
6. ($50.61): bGhOnEy10
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): 446a42, 07ac7c, 26c8d5, randybg926, ChollodronesBG17, TS100, Xmax100, chollodronesBG17, 502C6B, e2bcea, elec, rebajasBg17, f66bcc, 30Can, aff7off, BGTSDSI, BGTS100es, BGss506, BGTS100PL, BGsolder15, BGATS100, RandyBG926, BGTS100SP, AFfbG10, BG13TS100, BG23SW, BGCITYADS2019, BGDOMOTS100, BGSPTS100, BGVDay10%off, BG15PTools, 1691d4, BG12all, BG0313, BGdragonBoat, BG984214UK, BGSS10%SW
(there’s a little possibility that old coupon will work)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – TS100 65W TS-B2 Programmable Soldering Iron [EU] ($-3)
Price history and price alert
Price history (for all/most countries) for TS100 65W TS-B2 Programmable Soldering Iron is here.
Price records source(s): Gearbest, 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)).