Back end does look funky. Price might be ok depending on how much training she's had and if its in the discipline you want to ride her in. HOWEVER, 5k is pretty **** expensive IMO, unless she's some super show horse.
She looks to be a true black, which is not common. This is the type of black that does not fade in the sun and there is NO white on her.
That being said, she has a steep croup and a somewhat straight hind leg. Her front pasterns are very steep and straight. She actually stands (in that photos) like her front feet hurt her a bit. Maybe navicular? Another photo on better footing may help a lot.