You're likely looking at around $2000 price difference between the one larger vs 2 smaller contract purchase. I think many people find they actually need less points long term than they think so you might consider an in between purchase and see how it goes, esp if you find a good contract that's not quite 320.
WORD.
I rushed out and bought 310 points (160+100 on resale market and 50 direct). We are visiting Disney 3x/year on those points, staying in studios. That's a lot of Disney!!
BTW, OP, I LOVE BLT. It's a wonderful resort and I can't say enough good things about it. I hope you enjoy it as much as my family does.