Subaru 2001 Outback H6 3.0L Engine - Test Drive... what to look for?

My wife and I are looking at purchasing a used Subaru. We found a 2001 Outback what I think had an H6 engine... if I have the name of the engine wrong, all I remember for sure is that it's the largest one they made that year. It has 185,000 miles with an asking price of $4895. The interior is in surprisingly good shape as well as the exterior. We decided to check it out the other night and it was actually unlocked! I noticed the passenger side back door does not open from the inside and it appears they have not detailed the vehicle for sale yet. It has two moon roofs, a CD player, heated leather seats, electric windows, etc.

WHAT PROBLEMS SHOULD I LOOK FOR?
We are test driving it tomorrow evening. Any known issues I should be aware of?

IS IT WORTH PURCHASING THIS VEHICLE AT THIS PRICE WITH THESE MILES?
How does the price seem to you? Due to the door problem and car needing to be detailed, I am thinking of using that as a reason to offer less.

HOW IS THE ENGINE TO WORK ON?
After working on my 2000 Olds Alero and discovering all of the joy involved with dual overhead cams, I have to ask. How are these Subaru's to work on? Are things easy to get to? I see a few Subaru's cruising around every day so I imagine parts are easy and cheap to come by. I'd appreciate any input you might have. I am not a mechanic but usually dive head first into a job and figure it out as I go.

Thanks for any input! :)