here is what I would do, and have done before. It is a little devious.

Knowing that dealer Service Writers get a commission on what they write up, and that the answer to a question on your car is usually "Bring it in, we have to check it out", I created an imaginary daughter at a college far away who drives a Volvo just like yours.

The question to the dealer is "My daughter is at college in (Amarillo, in my story) and there is a problem with her car. She took it in and they said "It needs __(whatever your problem is)___ and they told her it would cost _______ (Select a number close to your estimated cost, like $674) so I am asking you 'That seems pretty high to me, is it a reasonable number to you?'

Then you have an idea of a max cost. Your mechanic might be less.

Next I guess at the time, for me that is double whatever the dealer told me.

The rest is more a "gut feel" thing. You have the info of cost, your own situation, time, tools, workplace and knowledge. Make a good decision.

Good Luck,

Bob (in Houston)

:>)