$14.99 – DIY bluetooth Speaker Kit with FM Radio 87.5-108MHZ DIY Soldering Project Practice Electronic Kit Solder Assembly Support U Disk TF Card AUX – Full Set.
According to my DB the lowest price is $14.99 for DIY Bluetooth Speaker Kit with FM Radio 87.5-108MHZ (in Banggood). You can create price alert here, copy coupons and view price history. Best price?
Latest price update (UTC time):
Banggood ($14.99)
Banggood warehouse is located in China. Too bad there’s no coupon right now in Banggood. What about the price? It looks like it’s a good price (lower than average ($15.03)).
Link: Banggood product page
Price: $14.99
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGCOMDIY5
(I don’t think these’re gonna work, but you can try ’em 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 DIY Bluetooth Speaker Kit with FM Radio 87.5-108MHZ. The lowest price was: $13.99.
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)).