A "broken timing belt" and a "cracked camshaft"? Really? BMWs don't have timing belts - those are in Hondas and Toyotas. Sounds like a load of horse manure to me. Unless you have bent valves, a cracked piston or cylinder wall, or some other major damage, it's fixable. Also, if the engine turns over, it's not that serious, particularly if there are no holes in the block. Does it make noise when it turns over, like something banging against something else? Oil starvation will spin bearings, causing a loud knocking noise, but the engine will sometimes still run. If the engine froze up due to no lubrication, that's a more serious matter. Timing chains and camshafts - even the entire cylinder head - can be replaced. I'd definitely talk to an Indy or another dealer for a second opinion.
I had a similar experience with a Turbo Beetle in 2000 where it spun a rod bearing at less than 1,000 miles (no fault of my own). It was fixed by replacing the engine block - a "long block" (block, crank, pistons, etc.) and all the ancillaries were removed from the old engine and put on the new one. Wanting to replace your entire engine sounds very suspicious, especially based on the information you've provided.
2013 F30 335i M-Sport 8AT/MPE/MPPK, 2011 128i M-sport Cabrio 6MT/PE
Last edited by roundel335; 10-24-2012 at 08:33 AM.