Liquid Damage in my Logic Board. It won't charge!

My Macbook air was working fine but it won't charge when connected to a charger. I've tried 2 chargers. So I took it into a designated Apple/Mac store and they ran diagnostics and determined that I had liquid damage (unbeknownst to me) to my logic board. They want to charge me $599 to fix it! What are my options? Is there any other place I can take it ? I am NOT computer savy and am scared to even attempt to fix it.