I've helped, advised and in some cases commissioned work from a number of new players to their first 2s purchase in Freedom and Global chat, just in the past three or four months - so it was clearly an incentive for some. As other have said, 2s was reachable in play for those who weren't invested enough 'yet' to part with real money, but invested enough to do some work to try prem (and those have got to be the ones mostly likely to convert to longer term players, surely; the ones not daunted by the hard work?)
5s is a lot more to earn without premium skills already or a good knowledge of the game and buys just half the amount of game time for a new person for more than twice the price of the 2s system. That feels fsr less achievable.
For me, never having had a priest, my small handful of 2s alts allowed me to make mayors for other deeds I founded and planned to found who weren't at risk of disappearing and could gain enough caring slots in the month to keep a wagon's worth of horses and a pet indefinitely. I'm probably in the minority here, I realise, but basically the two 2s alts on my side, even if they never premmed again, each guaranteed another deed with longterm upkeep. They brought in more money for CC than just their initial prem price and weren't just depriving you of my money in SMCs and LMCs as cheap storage (which I don't buy either way).
The higher price prem option won't stop me if I really want another, but it'll sure make me think a lot more carefully about it, since what used to be a mere 7s to explore a new whim or community endeavour or nice use for a particular bit of land will now be almost double that each time.
Just... adding an alternative use to the much debated sermon alt and storage alt losses here.