The cost of the miner in BTC goes down as the price of BTC goes up. That's why it helps ROI. On batch 2 the BTC price was dropping during the sale period so the ROI got worse the longer you waited to buy.
people need to stop looking at it this way. it just doesn't make sense. the machine mines btc not fiat.
You are confused. What I'm saying is that the machine is priced at $3200 on the web site. If you were to order it today at a USD/BTC price of about $500, you would pay about 6.4 BTC. If USD/BTC goes up to $1000 you will pay 3.2 BTC. Paying 3.2 BTC is much better than paying 6.4 BTC.
I paid 5.5 BTC for batch 2. Others who ordered later paid a lot more (in BTC). I may ROI if I'm lucky and everything goes perfectly. They won't.