I am just a pianist, and not a tech, but yours is a 5' 1" grand, with a retail value of around $10,000. Since the price usually paid is a percentage of retail, the price is not a bargain.
https://www.bluebookofpianos.com/fairtrade/conover.htm I could not find a serial number with what you have provided, but the link provided above has a phone number for Samick, which is the manufacturer now of this brand. They should be able to help you find the year of manufacturer. The fact that it is no longer produced is of little concern, as piano parts are not brand-specific, and many old pianos have been excellently restored.
Paying $7,000 for this piano (if you consider the rental as part of the payment) seems excessive because of the size as well as the brand.
The question is: if you do not invest the extra funds in the piano, would you have sufficient funds to start over? I would recommend that if you are considering the purchase, you pay for the services of a tech to evaluate the piano condition as 'restoring' a piano can mean many different things to different people. The pro side of looking at keeping the piano is the relatively small additional investment you would need to make and the fact that you like the sound.
If you need to find a tech, you might start with Piano Technicians' Guild
https://www.ptg.org/Scripts/4Disapi.dll/4DCGI/cms/review.html?Action=CMS_Document&DocID=19&MenuKey=Menu27 although certainly excellent techs are not members.
If you decide to start-over your search, I would let the independent tech that inspects this piano know that you are looking. I found my current piano through my tech. In addition, you should have any potential purchase of a pre-owned piano inspected by the independent tech. Don't skip this step!
Hope this helps a little.
EDITED TO ADD: Another possibility is checking with the dealer whether the $4,000 could be applied to another piano.... if you decide you do not want to purchase this one. Again, I would have an independent tech check out the proposed purchase