Will it be economic to mend my TV?

My Sharp 66FW-53H TV has just gone bang - literally. While I was watching it there was a small crack/pop and the screen went black. If I turn it on the standby light comes on, but the screen doesn't power up. (You can't hear it humming.)

The TV cost £430 and is three years and 4 days old. I suspect it will need a new power supply and with the labour cost likely to be £50 I'm not sure it it will make much sense to get it repaired.

Can anyone estimate how much the power supply board is likely to cost me?