At the height of the post-9/11 mess I bought a o/w DL bizclass BOM-FRA-JFK for US$1,500 (such a deal) with a layover in FRA and got the following (in round numbers):
-- Base miles 7,900
-- Double for BOM-JFK: 7,900
-- Double miles PM: 7,900
-- DL Amex purchase: 1,500
-- DL Amex double miles: 1,500
-- Class of service: 1,975
-- Web ticket bonus 1,000
TOTAL 29675

I think there was some other bonus, because my recollection is that I ended up with 31,000 miles. In any case, it was enough for a free domestic ticket with a few miles left over. Total cost: about 5 cents per mile.