The main issue here is what sorts of food you want to feed your crew. Keeping it to jerky and tack would reduce the cost to roughly 1g/person-week as per the equipment list in the PHB. Therefore one "cargo point" of jerky and tack would be 600g (1g x 25 people x 24 weeks).
However that's playing it thrifty. When you want to have a well balanced meal with all the good nutrients, then you could say that a "Meal (Good)" would cover the bases at 5c per meal. At three meals in a day, that skyrockets the fresh food cost for 25 people to 3.75g/day putting the cost to about 630g for one "cargo point" (26.25g/week x 24 weeks). But even then I would assume minimum fruit and veg intake, but livable, and spoilage goes up.
Where five doses of fruit is 10c, 50c to prevent scurvy, you're probably going to see an increase of 7.5g/day (averaging the two, one serving per person per day) per point for a whopping 1,260g for the fruit alone.
Beyond that there's always seasonal as well as supply & demand issues to account for but that's up to your own tastes.
EDIT: I found a book called "Ships & Sea Battles" from the Swashbuckling Adventures line (so post d20 half-port) that includes costs for your average cargo holds. In specific there is a chart for perishables and what it would cost by nation. Since each different food item type by nation is an entry it's difficult for me to post here.
EDIT2: Averaging two trade routes between the seven primary nations I have assembled the following list containing the approximate cost in guilders for one cargo point of a given item. However, one shipment of most of these things was usually calculated in at least two cargo points, always with more for fresh/easily perishable items for containment, storage, etc.
- Fish, Salted: ~228.57
- Fish, Smoked: ~216.07
- Beef, Salted: ~244.64
- Vegetables (Broccoli, Spinach, Lettuce): ~257.14G
- Vegetables (Peas, Beans, Corn): ~264.29
- Vegetables (Tomatoes, Squash, Onions): ~239.29
- Citrus Fruit: ~339.29
- Cheese: ~464.29
- Mead, Ale, Beer: ~1,297.62
- Wine: ~1,052.38
- Potatoes: ~271.43
- Rice: ~266.08
- Wheat: ~265.63
- Butter/Milk: ~313.40
If I wasn't concerned about copyright stuff I would have just posted caps of the two charts.