My pedal cannot get attached to the crank because the crank threads are worn/stripped. Based on this link, the solution appears to be to drill out the threads and insert a helicoil. I approached a repair person and proposed this solution, but he immediately said that I would have to actually replace the crank itself, his reasoning being that helicoils tend to fall out while riding. On top of this, he stated that I would have to replace the pedal too. (As a side note, he mentioned that I'd have to pay for a crank set and pedal set because these products are sold in pairs.) I am substantially skeptical that this amount of repair is needed. I frankly think he is attempting to get as many parts used in the repair as possible. Perhaps he receives a commission from his supplier(s) based on parts sold.
Is this degree of repair actually appropriate, or am I simply being ripped off? I have attached a one-minute clip and a few photos describing the issue at the following Google drive link. Note that the video is useless after the 30-second mark as it starts to blur. (Also, there is a piece of aluminum foil that is in the spindle hole in the video. Please ignore that — I was naively trying some things out!)
Any and all help would be appreciated!