I wouldn't recommend Sagittarius A* passenger missions for casual players. I wouldn't recommend them for anyone, in fact.
If you wish to make money from long range tourist missions, you can often get much better payouts per time by sticking to destinations 1-5k ly out. There's also a little trick to getting much better payouts: look for missions with 7 or 8 first class passengers. Above six people, the reward for more passengers scales up much more than it does with distance. You'll need a size 6 first class passenger cabin, of course (5C can only carry six passengers), but plenty of ships can fit those. Look around in wealthier places where you are in good standing with most minor factions: you'll often need friendly or cordial rep for such missions.
For example, I recently did a tourism mission to 2100 ly or so, carrying 8 first class passengers. The payout for that 4k round trip? 25 million credits. Granted, this was an outlier, but generally you should be able to get 8-16 million credits for staying within 3000 ly. Do a few of these, and you will more than match the rewards for one of those extra long distance missions. (Even if you would score a mission to Sag. A* with 8 first class passengers.) Plus this way, you'll see many more tourist spots than if you just went to Sagittarius A* or Jaques. And the timer is still the same, so with such distances, it's practically infinite.