IMHO, Blue Book values, ratings, and evaluations as to condition are wildly inaccurate. Luger is a fixture in weapon collecting community, interest grows with each generation. If a Luger is considered an investment, then it can be 'flipped' within days (if not hours) while a Remington 740F is a niche item which could take months to sell. That could be a telling point if your grandson needs that college money quickly.
Remingtons have no 'history'; every Luger has a story. Some just humdrum housewife; others supermodel beauty queen.
OTOH, a Luger is not a Faberge egg. If it means nothing to you, and you like looking at the Remington better, then do the deal.
Like Alvin, my own opinion.