Always get the inspection BEFORE you hand over any money. I don't care who the seller is. Even if you trust them with your life, they may simply clueless about cars.

$10k is a lot. I'd consider flipping it on one of those dumping grounds like carvana.

 

History reports are okay. What's on there is usually accurate but a lot can be left off including major accidents. I've seem plenty of cars with major accident repairs but clean history reports. Very well maintained vehicles may have no record on the report. The only reliable info is where the car was registered. Here in the south we avoid cars from up north like the plague.

Seeing a leak rarely means a system has to be replaced. It's usually the hoses, gasket or seal. A leak can look dramatic with oil and dirt crusted all over it but it just has to be cleaned up and diagnosed.