Have also been recently looking at AP's. This link may be helpful:
https://www.audemarspiguet.com/en/se...rvices-prices/
1450 CHF for a chronograph so just over £1000 for a service at current exchange rates.
No idea about waiting times for that model but I think some of the Royal Oak models have fairly long waits but I'm sure someone more knowledgeable will be along shortly