Alignment- Dealer said that one tie rod is seized

[fmugur]

How common is this problem? I went to the dealer to have an alignment done and they said that the left tie rod is seized. Is this something common or they are just trying to get more money from me (+$312 part and labor).
I went to have the alignment because the rears are worn out on the inner side to the strings (315s for 20k mi) and I am going to put new tires. The front tires look very good. Couldn't they just verify the front wheels alignment even with the tie rod seized? thanks in advance