Most prices in the bazaar are not insane. They are based on pure economics. Supply and demand. DI and RGC are rare spells, and ones that raiding clerics HAVE to have at the higher end.
As such, they are worth a lot. If you cannot afford to buy them, camp the spell, or the components. I cannot tell you how many days I spent in PoM, killing the halfling guards before Yaeth's pg. 73 right dropped. But I did it, because I wanted the spell.
Basically it comes down to this. If someone sets their price too high, the item will not sell. If the item sells, then the price was not too high. If an item sits long enough, most sellers will lower the price until it sells.
Look at the Benevolent Girdle, as an example. It is a really nice belt slot for paladins. However, it is WAY cheaper than some other belts with worse stats. Why? because it is a common drop, is only wearable by paladins, and to top that off, many paladins have haste belts in that slot, and don't want to give up the haste for the stats.
Similarly, muramite runes are a lot cheaper than minor muramite runes. Crazy? Nope. Just the result of more people grinding in WoS, where muramite runes are common, than in DH/Bloodfields, where the minor runes are more common. So, higher supply of muramites, with similar demand, results in lower prices.
Note, I play a cleric, and had to obtain all those spells, and I see no problem at all with the bazaar pricing. The counter argument could be made that it is greedy to want someone to give you the spells, for less than they are worth.
The economics side of EQ, is a part of the game many people enjoy. I know people who's mains have never hit level 30, yet they have 300 in a tradeskill, and make lots of PP in the bazaar, off the fruits of their labor. Why is their playstyle somehow less valid than yours?