On the HP-150 "no display" and "no beep" often means a broken video board which is tedious to diagnose and fix. Additionally, there are two standard battery cells on the video board which leak when not removed and they may destroy more.
The keyboard (46010) is not so easy to find - it is no HP-HIL keyboard but a serial one and was also used on some HP terminals of the same era.
Without knowning more details, $100 seems to be on the high side of life - at least for me.