Apple iMac 27-inch, 2012 model, with box and original 24GB RAM

【Junk Item】
iMac 27-inch (Display: 2560x1440) 2012 Model
Processor: 3.2GHz Intel Core i5
Memory: 24GB (4 sticks total) 1600 MHz DDR3
Top-tier customized (CTO) model of its time
High-end configuration: GeForce GTX 675MX (1GB)
Graphics: NVIDIA GeForce GTX 675MX 1024MB
Includes original power cord and box.

*Keyboard and mouse are not included.

This unit was recently used under specific circumstances.
It technically operates without issues, but the internal hard drive is broken. It can be recognized by Disk Utility, but the internal HD does not boot up (it has not been sent for repair).
Other than that, there are no problems (monitor and specs are functional), so I have been booting it up using an external hard drive with the OS (macOS High Sierra) installed. To boot, first turn on the external hard drive, then turn on the main unit. The mail app takes a while to launch, but it's unclear if this is related. I used it for work without any issues.
The second to last photo shows the ST1000DM003 Media HD, which is the broken drive (only 4GB capacity is recognized).

For shipping, the box will be reinforced with tape to close it securely, and the shipping label will be affixed to the box. If you wish to avoid damaging the original box, we can pack the box inside a cardboard box for an additional ¥1300.

*External hard drive and OS are not included, so please prepare them yourself.
*The memory is also upgraded with 4 sticks (24GB) installed, so it can be used for parts harvesting.