Parchements are the easiest to get, usually get a free MQ from a guildie, or they are cheep in bazzar. Glymph Rune Words are hard to get, they drop off of named in BoT and SolRo tower most commonly, but still not easy to get by no means. Minor, Lessor, and Murramite Runes are droppable, so you can buy those in bazzar, but the greater, glowing, and ancient are not, there for you need a n MPG, RSS, or the like group to get those spells.
61-65 - Parchments/GRW are not droppable, but the spells are, so you can buy them in bazzar.
66-68 - Murramite Runes are droppable, but the resulting spells are not
69-70 - Neither the Runes, or Spells are droppable, you gotta get those yourself : )
Lots of luck, im still working on most of mine