Remark your requirement, 1USD/1PCS, eg.  HC05/HC06+HC02, cost 15USD, then check out 15PCS * 1USD

Acrylic case,

Acrylic "L" Case for Nextion 3.2 inch  (+$10)
Acrylic "L" Case for Nextion 4.3 inch  (+$12.00)
Acrylic Protect Shield board for MMDVM HAT (+$1)

Alloy case,
Bare Alloy case for RPi 3B  (+$10.00)
SanDisk SDCard 16G C10  (+$4.00)

5V2A USB Power supply wire with data transfer (+$2.50)

Bluetooth Model ,For Nextion replace USBtoTTL ,replace 4PINs
HC05/HC06+HC02,cost 9USD,including:
(1)HC05/HC06 (+$5.00)  act as Master
(2)HC02 (+$4.00) act Slave

NOTE:
1) Contact me first bi7jta@gmail.com
2) It is strongly recommended to use with BI7JTA Product ,obtain more service.
3) If more than 1PCS and out of stock ,purchase need time wait.

Shipping cost check out

https://www.bi7jta.org/cart/index.php?route=product/product&path=61&product_id=51