Definetely not true in all circumstances and if a non mm wants those calls I guess you can get better than par, but european option markets are not very crowded ime hence - from limited experience- I ended up several times with ditm calls sold slightly below par or at best when the underlying bid reached my selling price (happened last monday or friday with BMW March 20 calls ).
Earlier this week I tried to sell 14 calls expiring thursday evening at .94, stock price reached 14.95 and bid at least 14.94 but couldn't sell a single call.From there the price went south, ugly.
If you add the transaction tax of 0.1% in that case and the commission from IB, exercising the calls will cost about 0.0194 per share. i'm not sure how a mm calculates his cost, but he must be buying slightly below par.
Another problem, like in the case above is the large number of calls i tried to sell, mm couldn't hedge himself with the underlying - still I had hoped to sell a few calls.
Also when prices were moving very fast, I've sold calls several cents below par. The sweeter thing in that case is the ditm calls were already largely profitable and didn't feel too sad.
