I don't think any digital camera holds its value and it's better to think of it as a 3 - 4 year rental paid up front. On that basis, an M8 costs about £15/week.
Leica is first and foremost a lens manufacturer and that is where there is somewhat better value retention. For Leica, the need to produce bodies to mount their lenses on is an inconvenience, as is the business of actually producing an image from the captured data.