I don't know if it's the only reason, but it takes 160 points to trade into Interval International for a 1BR in low season. Maybe they decided to sell all new contracts so that the trading option would be there, instead of having people come up 10 points short when they wanted to trade.
I haven't ever traded out with my points, so I don't know if a lot of people do it, but that could certainly be one reason.