That price could be a good price... or it could be totally too high... depending on condition. Without knowing what condition it's in, giving any kind of value estimate just can't be done fairly.
If she's considering buying a vintage RV, she MUST know or be willing to learn a lot about them as well as the mechanical terms used or it will eat her alive in terms of money and frustration if it isn't in nearly 100% solid shape in terms of mechanical things, body, and appliances. Vintage RVers are, for the most part, do-it-yourselfers because of the expense involved if you have to pay mechanics to do the work. Like a marriage, it's not something to enter lightly and unprepared. It's the difference between being able to take on the challenges that go along with the benefits of owning a vintage RV and possibly having the worst experience ever.
To the right, the lower side-block - RV buying checklist. Download it and take a good look at it. This is how a good evaluation is done. If she can't do it herself, then she absolutely needs someone who does to help.
If you think of it in familiar terms:
Check the chassis as though you were buying a car.
Check the Coach as if you were buying a house.
Maybe a travel trailer would be a better choice as a starter RV and a good way to learn the ropes.