What parts of my white screened iPhone 3GS need replacing?

Hi,

I recently fell in the pool with my iPhone 3GS in my pocket. I turned it off and put it in rice for a couple of days. Then I plugged it in and it began to go onto the apple symbol then cut off and loop. When removed from the charger it would turn off instantly and not turn back on until plugged in. I could get it to recovery mode by holding the home button. It would not restore. After doing some research I found that it was a battery issue and replaced the battery and restored it. It worked fine for 20 hours until it died. When it wouldn't turn on I assumed it was out of battery and plugged it in. It did what was above except it didn't have to be plugged in and it couldn't get to recovery mode. I left it charging and came back to it white screened. I could hear voice control when the home button was held down. I restored it and now it just is white screened. When I press the lock button it locks and then when I turn it on it goes to white screen. I can get a new LCD for $30 or with new glass and a touch digitizer for $45 (NZD). What parts need replacing and is it worth fixing it?

Thanks in Advance,

Paddy