Honda insight head problems - HELP!

My wife owns a 2000 insight. 2 years ago we took it to a Honda dealer for service and supposedly the spilled antifreeze everywhere. so we smelled it. next time we took it in we told them it still smelled. they cleaned the antifreeze but said there was no problem. the next year or so we would smell it occasionally but the dealer said everything was fine until we started to lose some antifreeze. now we are told the head gasket is blown, the thermostat is bad and they had to pull the head. maybe it is cracked maybe not. $1200-$2400 FIX IT price. What are the risks to replacing the head only? I dont know enough about all this. Is it the dealers fault for not finding it after a few times of us complaining??? Honda has lost my business for life