ATM you can buy FNIRSI DSO153 2in1 Portable Digital Oscilloscope Signal Generator 1MHz 5MSa/s for $29.99 (in Banggood). Basically copy coupon, view price history or create e-mail price alert. You probably want to know what is the best price?
FNIRSI DSO153 2in1 Portable Digital Oscilloscope Signal Generator 1MHz Bandwidth 5MSa/s Sampling Rate Compact Electronics Repair Tools 1000mAh Battery USB Charging Diverse Waveforms – Upgrade
Latest coupon and price update (UTC):
Banggood ($29.99)
Banggood warehouse is located in China. I don’t think there is an active coupon right now – at least in my database. Good or bad price? Hmmm, price is higher than average (which is $27.82 right now), so better set price alert down below…
Link: Banggood product page
Price: $29.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
There were country-specific coupon codes published on Couponsfromchina social channels and price alerts. Coupon price may vary by country, because there’re different VAT rates, shipping cost etc. There is a chance that some latest coupons are still working:
1. (26.6.2024, $24.99): BGRJU6DSO153
Item: FNIRSI DSO153 2in1 Portable Digital Oscilloscope Signal Generator 1MHz 5MSa/s
Countries: Greece, Portugal, Spain
2. (7.6.2024, $21.60): BG24MA605
Item: FNIRSI DSO153 2in1 Portable Digital Oscilloscope Signal Generator 1MHz 5MSa/s
Countries: Germany
3. (6.6.2024, $26.99): BGRA209
Item: FNIRSI DSO153 2in1 Portable Digital Oscilloscope Signal Generator 1MHz 5MSa/s
Countries: Belgium, France, Italy, Luxembourg
4. (23.5.2024, $27.00): BG20fc81
Item: FNIRSI DSO153 2in1 Portable Digital Oscilloscope Signal Generator 1MHz 5MSa/s
Countries: France
5. (8.5.2024, $28.99): BGRMAYIT2S
Item: FNIRSI DSO153 2in1 Portable Digital Oscilloscope Signal Generator 1MHz 5MSa/s
Countries: Greece
Old coupons (from the oldest to the newest): BG32759c
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Aliexpress
There’re some similar (or not) items on Aliexpress
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 FNIRSI DSO153 2in1 Portable Digital Oscilloscope Signal Generator 1MHz 5MSa/s.
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)).