If your oil level stays up, there is just a problem with the oil level sensor. The motorists of the world got along just fine for about 85 years before low oil level lights were added to instrument panels. It is NOT worth $1,000 to fix this IMHO.
The timing chain will have nothing to do with oil pressure. Also, this particular engine has a ratcheting tensioner and is NOT known for breaking timing chains. You would be best served by checking for stretch and if there is none, then wait until the engine must come apart for some other reason, then change the chain while you are in there. If you have to remove the timing cover to reseal, that might be a good time to change the chain.