As Flem pointed out, that would generally be true, but not always. IMHO, two great series that are available are the RJ Spagnols "Winery Series" (15L) and the Cellarcraft "Showcase Collection" (16L), both outstanding. Both usually come with grape packs for the red varieties. On the other hand, I have made the Mosti Mondiale "Original All Juice" (23L) and have been somewhat disappointed in the reds while the whites seem okay. Further, the Mosti Mondiale "Rennaissance Collection" (16L), at least the Valpolicella, is good. There does not seem to me to be a hard and fast rule, just a tendency.
Bear in mind that you are also paying to ship water with the bigger kits (which you have readily available, I am sure) so there is a balance that has to be struck there. In my limited experience with kits (I have made 20 since January) I am most pleased with the two series that I mentioned above. I am sure you will get other views on this as it is a somewhat subjective exercise.