O1 and most other high carbon steels in small sizes seem to be hard to get lately for some reason. Gameco/Artisan Supplies is pretty much out of anything useable on a small scale.
Try here: Great deals from Maker Material Supply in Blade-Steel- | eBay Stores
I have used them before. Postage is not too bad and they are very helpful with how much to order to maximise your postage dollar..
My latest order was four pieces of 1/8" x 2" x 12" O1 steel and was about AU$70 posted.
They usually recommend O1 for travisher blades as it can be cold bent in its annealed state. Not sure if you can do that to the same degree with 1075 or 1084. If you have a forge and anvil then you could use the 10-series steels and shape them hot. Whichever steel you use, you still need to harden and temper the blade once it is shaped.