Well it just depends how adventurious you are. If you like to stick with common flow - GBR (400+$ for one) is good place, or you can phone up reiders and poke them - they may have stuff, but i am not aware of their pricing for LR stuff. Also you can sit and wait till someone sells used ones.
If you feel like trying less travelled road - you can get Series 24 spline gears. They have stock gearing of 4.75 and will cost you between 140 (and no, i am not kidding) to 200+ per r&p. Unfortunately to go that road you will also have to change flanges, but they like bugger all - 25$ per thingy, or something like that.
I heard some complaints about them being weak, but they mostly coming from very ******** crowd. Other than that - its straight drop-in replacement (with exception that you may need ARB spacers for rings, to set them up properly).
If you feel like going that road - give britishpacific buzz (i think its best prices for the moment, and if you ongoing customer they will drop in discounts for ya

).
I have those and they are getting me around moderate trails in CO with no issues.