Oh, I made a little weedy comment earlier -- we can't switch to a settler yet, since we're only at size 2! We don't grow to 3 for another 3 turns, yet we'd finish the settler in 1. So...I think granary is our best option.
320 gold for writing, eh? Time for some guesstimating, a nice Fermi problem here...
We're currently at 5gpt on science. Granary in 6, settler in 4, I think. Then it'll take us about 4 turns to settle either #1 or coastal #2. That's 14 turns at 5gpt...for a total of 70 beakers invested. (The number 5 will go up when we get mp, it'll go down when we get granary maintenance fee, it'll go up when we grow, it'll go down when settler is born...so I think 70 is a decent guesstimate). That leaves 250 to go.
Coastal #2 will give 4g in the city center, plus one more when we get another tile roaded. #1 will give 3g in the center, +2 for a roaded river tile...I think our second city will give 5gpt at first, -1 for corruption. With our capital pulling 5...that's a grand total of 9. Carthage can grow in 5 with the granary, so let's say it takes another 14 turns to settle our third city, so that's another 126 beakers. 126+70 = 196 @ turn 28. 124 to go.
With a third city, that's another 4gpt, so that makes 13gpt. 124/13 = ~10 turns. So I guesstimate writing in 38 turns. Hows my math?
The alternative is writing in 50 turns, while saving 300 gold or more. So if I'm anywhere close...I think I vote for max research...saving 10 turns is a lot, and I'm not worried about getting behind on tech for now -- if we are on an island, all we want is curraghs and settlers and workers and a few cheap mps for awhile...and if we get philo first, we'll have no problem trading ourselves up. What do we need gold for?