I would save the points till you have enough to buy all 80 fragments dont spend them bit by bit in case you get that pet from draw. Also once you get all same runes to lv 5 id sell new runes of same type to get fragments. Personal preference obviously.

No dont sell the level5 i mean once all your equipped runes are level 5 you can sell the excess for points because it takes a lot to get to lv6. but its personal preference whether you want more summons or more power .