Apply in person at CVASC, and have passport posted back

Just a few questions:

1. Is the cost for this £175?
2. The processing time is suggested at 10 days. Does this mean it will take 10 days for them to just approve the entry permit or does it include the time for the passport to arrive in the post?
3. Anyone have experience of visiting the CVASC in London and having the passport mailed back?
4. When does the 90 days to enter China start from? The day of my appointment or when the visa is approved?

Cheers! Jake