It does not cost anything, it is a short range communication protocol and does not use your data plan.
If you make devices and want to implement bluetooth functionality: Yes.
There are licensing and certification fees that your project needs to budget for.
How much does Bluetooth technology cost?
It looks like the standard fee is $4000 but for small companies a $2500 license is available, and for a GATT client profile only there is a $99 option. I have used some of the cheap $3 Bluetooth modules in some projects but they are not presently offered for sale, so it might not apply.
Does turning on Bluetooth use data?
No, using Bluetooth doesn’t count as data usage. However, if you’re using an app that accesses data while using Bluetooth, you’ll use data through the app. For example, if you’re listening to music on the Pandora app with wireless Bluetooth speakers, you’ll be using data to access the app.
Can you use Bluetooth without service?
Bluetooth. Bluetooth is only used to transmit signals over short distances, and it has nothing to do with your Wi-Fi network or cell service. You don’t even have to have a Wi-Fi or cell network available at all to connect Bluetooth devices, it’s a totally separate and different type of technology than those other two.
How does Bluetooth work?
A Bluetooth® device works by using radio waves instead of wires or cables to connect with your cell phone, smartphone or computer. So when Bluetooth-enabled products, such as a cell phone and headphones, are in close proximity to each other, they connect, or pair.