I agree that as they are being published, Runequest books are too expensive. I probably have a lot more income to budget for RPG stuff than most players and GMs, and even I can not afford to run a Runequest game in Glorantha. If they would publish the same material either in softbacks or in hardbacks twice as thick, it would be a lot easier for me to keep up.
I think this constitutes a serious barrier to entry. People look at Runequest, and they look at D&D, and buy the D&D books because while the books themselves are more expensive, each book gives two-three times as much information, and you don't have to buy half a dozen of them.
Hardback adventure books are nice. I have the Witchfire Trilogy (320 pages for 35 dollars), Expedition to the Demonweb Pits (220 pages for 35 dollars), and Expedition to Castle Ravenloft (220 pages for 35 dollars). Paying 25 dollars for 104 pages is something that really has to justify the per page expendature.