You're better off getting a new/used one (which looks like they go for around $60 on ebay). It would basically be a different phone anyway, and yes you would have to unlock it and do everything again because the memory for the phone is on the circuit board apart from the sd card.

So I did something kind of stupid. My phone got wet and I didn't dry it up enough before I turned it on and I fried something in it. Now my question is if I replace the circuit board will it work again, and if it will work will I have to unlock it again and will I have to install android on it again, basically what are the consequences to replacing the circut board. Btw I have an LG Thrill and I use it on T-Mobile if that helps at all.