The 19" RCA TV that I have in my trailer is on sale at Superstore this weekend. It's on sale for $80, then they have double no GST on top of that. So with tax and environment fees you are looking at a total price of $80.
I haven't opened that on to make 100% sure it still has the 12 volt input, so maybe ask them to open the box before you buy it.
Then grab yourself a power adapter like
this one and you have your 12 volt TV for under $100. (I have bought 3 of these adapters from this seller.)