Dual Spec Problem

Hello I made a Blood Elf Priest in Frostmourne realm WOTLK and selected shadow specialization at the first cuz i thought it would be hard to destroy mobs at the first levels with disc (yeah im kinda a newbie ). Then my friends needed a healer in dungeons and i turned into disc healer but since my specialization is shadow i dont have penance ability and now I want my second specialization to be Disciple but 1000g is too much what do you recommend me to do?

Stop changing specs to much. You can comfy heal dungeons with shadow spec up to level 60 like I did.