I think you are unlikely to find anything at that sort of price range, which is about 60¢ per sq ft. You would, however, probably want to go with something a little heavier for the wider paper and would generally get free shipping for that quantity – I don’t know how much RR charges for shipping.
Canson Rag Photographique 310 is a little whiter, but no OBAs, and is $1.92 per sq ft in 44 inch rolls. Hahnemühle Photo Rag 308 is also a little whiter, has very small amounts of OBAs, and is about $2.04 per sq ft (the rolls are less expensive than Canson’s, but are only 39 feet compared to 50 feet long). Moab Entrada 300 (actually more like 290 g/m² if I remember correctly) is about $1.60 per foot in 44 by 40 foot rolls.
I don’t what Innova’s pricing is like for their smooth natural whie cotton rag.
Brian A