Hi. You need to know the retail prices for everything when going to gun shows. Especially used firearms. Some dealers are looking for people who just don't know 'em. Cash talks loud if you see something you like within your budget. Haggling isn't a bad thing either. Just be prepared to walk if the guy doesn't want to play.
"...some soft point .243 for..." Isn't much use if her rifle doesn't like it. Cheap doesn't always mean good.
Her gun seems to like Federal (what I purchased), but It's only an H&R handi rifle and she'll probably never attempt a shot at a deer over 100 yards where we hunt anyways.
My m1 carbine isn't a 1 MOA rifle to start with (with me shooting it), so cheap is good there just for plinking.