Timing Chain Broke 98 Explorer XLT 4X4

After stopping at the grocery store I parked and went in, made my purchases and got caught at the door of the store by the "don't steal our carts" gates. I pulled my truck up in front of the store and turned it off to get out and load up. I went to restart and without the engine really turning much let alone turning over it sounded like my starter was not engaging the flywheel. I tried starting it and banging on the starter but still was unable to start it. I towed it to the a local shop and they determined it was the timing chain and were not equipped to do the job. I towed it to a ford dealer and they said that without tearing the engine down they would not know how much damage was done(i.E. Bent Valves, etc.) I told them how it happened and they are telling me that it will most likely be cheaper to replace the engine at $5200.00. My question is, how much damage can breaking a timing chain at startup, without the engine turning over, do to the engine? : :Shock: :