The HD is just storage. Install a new 1-2TB drive ($50) and boot up the system. You will go into the menu and click to reformat the drive. And off it goes.

What exactly is she moving forward with? If she is keeping a 10+ year old DVR system and all its components (that was a POS when it was new).

Look, this is what is available now:
16 ch DVR, (8) 5mp HD cams, 2 TB HD, and all the accessories for $539. You can't beat that. Anything cheaper than that, is probably going to be a steaming pile of vial.
[Link: supercircuits.com]
This is based on a Hikvision OEM.

What does this lady want from you? Is she playing the long game, thinking you will eventually pitch in your own money for her?