I did have a supplier, 3 actually. But it seems they noticed the insane increase in Ore and won't go below 65g a stack. Which is insane for Ore I used to pay 20g less for.
I'm not too bothered by long-time trends. For a while, I didn't buy elementium above 35g a stack, and did decent profit. These days, I'm lucky to get it at 60g, more often 70 or 80g, and I'm making more money than ever before, because the gem market followed the elementium prices.
Bottom line is, either use a spreadsheet to determine whether it's still profitable, or if like me you're a lazy bum, just jump in and buy a few dozen stacks, and see whether you make money.