2000 Dodge Dakota cracked head

My 2000 dodge dakota overheated in traffic and I had to have it towed to repair. The mechanic said it had a blown head gasket which he says head was taken to machine shop and 3 weeks later I paid 716.00. 2 days after picking the truck up same thing happened and now he is saying the head is CRACKED. I asked him WHY he didnt find the orginal reason this happened. He is saying the radiator needs replacing and then head work again. Can a CRACKED head be repaired? I was under the impression if your head cracks you need a new motor. Any help and info. You can give me would be appreciated. I may need to have this work done myself since I already spent over 700. Thank you