The unfortunate truth is that any number we decide on is basically an asspull. We don't know anything about the actual costs or the business environment. Traveller has extremely simplified, it is all the same everywhere values oriented towards making playing PCs with ships easy.
There's no information on spaceship insurance, no underwriting of cargos, no information on what a normal loss rate is, no information on how much management overhead the shipping route is paying for, no information on import/export taxes, sales taxes, the licensing fees.
Do they send a Galoof because the Florians limit the number of ships that visit, not the volume of trade? Is the Galoof the biggest ship that makes sense? Or just the biggest available in the region? Or is it not the optimum ship at all but just what they have?
The best route on the map might not be the best route politically. The Galoof's owner might have a factory on some less than straight line route. Or be banned from doing business on the more direct planet because of some thing that happened in the past.
What are the Florians selling (or buying) that makes going that distance to get it and what is the demand? Is that profitable price based on limited availability so that if I bring too much at once, my Florian Tulips won't sell at the price I need? Is the Duke of Tobia's addiction to Florian bobblehead dolls literally underpinning the entire market because he's a trendsetter?
Florian Trade could be literally the most profitable thing in the Reaches or it could just be another interesting trade route and both would fit the information we have.
I know it isn't that helpful, but the answer is literally "what would be the most fun for you?" because the setting is never going to dive into that level of detail to answer the question. And even if they gave the answers for Tobia-Floria trade, those answers wouldn't apply to Tobia-Aslan trade.