I'll second Polyglot's advice. Modern 150 and 210mm lenses are cheap and plentiful. You can find good used 1980s-1990s models from Nikon, Rodenstock and Schneider at very reasonable prices. These are the pre-apo plasmats. They're multi-coated and all are fine performers. Once the lens makers went to the super new designs the prices really escalated. Yes, they probably produce "superior" results, but you can pay a whole lot of money for what really is a small increase in performance.

If you want consistent color rendering, stick to lenses from the same manufacturer.

Focal length spread is a matter of personal choice. My basic kit is 90mm, 150mm, 210mm. Some prefer 75mm, 135mm, 180mm. A 240mm is going to be bigger and heavier than a 210mm, but there's something special about working at close distances with a 240mm. It throws the background out of focus just enough more than a 210mm to have a very different look, especially at closer working distances. I don't own one, mostly because I have a 210 and a 305. I'd love to have one, but really can't justify the purchase.

Good luck and good hunting!

Peter Gomena