Indeed. From Freestyle (some other sources may be cheaper) Efke IR820 and IR820Aura are $12.99 a roll in 35mm and 120, a bit over $2 a sheet in 4x5 (I did not know they made it in 8x10 and can't find that listed at B&H either.)
So would I pay $17-$18 for a roll of true IR film with Ilford quality control? You bet! Likewise, I'd probably pay $3 a sheet for 4x5, especially if it was faster, deeper IR stuff like the old Kodak HIE. That would be awesome. Hell, I'd probably pay $20 a roll and $5 a sheet, at least for some of it. I wouldn't shoot a ton of it at those prices, but I would probably buy a couple hundred bucks worth if it were offered yearly. Should keep a year in the freezer without issue, I'd think.