trigger in sql update table

Personally, I don't think that is a good idea. That's because you are essentially violating the whole idea behind the normalization. 

 

You already have a table1 with an Id column, you are storing that id in another table2, then typically you should be joining these tables in select query and retrieving the price from the table1. 

 

Please note that not duplicating information is the very essence of good db design.