I use helium in breathing gas mixes for deep diving. Last week I was quoted three or four hundred dollars for a full T bottle of UHP. Sorry I don't recall the exact price, only that it didn't break the bank. (There are less expensive grades. I use UHP because it's the least costly one with a total hydrocarbon specification from my supplier.) Right after that I started to have trouble with one knee, so diving is on hold for a bit. Divers in FL are reporting pricing of about a buck a cubic foot. Depending on what grade and how much you need, it might be worth a trip one state south.
The price I was quoted is not hugely different from what I was paying when I last did a bunch of deep diving. I have been told it spiked a bit while I did some other stuff, though. Maybe your local dealer's stock is from during the spike?