Level 4 prayer stone requires Lv 1, Lv 2, Lv 3 prayer stones, Archondrite x1 and 500,000 gold, this can result in the following:
Lv 4 Prayer Stone x1 [16.6%]
Lv 4 Prayer Stone x2 [16.6%]
Lv 4 Prayer Stone x3 [16.6%]
Archondrite x1 [16.6%]
Archondrite x2 [16.6%]
Archondrite x3 [16.6%]

Level 5 prayer stone requires Lv 1, Lv 2, Lv 3, Lv 4 prayer stones, Archondrite x2 and 600,000 gold, this can result in the following:
Lv 5 Prayer Stone x1 [16.6%]
Lv 5 Prayer Stone x2 [16.6%]
Lv 5 Prayer Stone x3 [16.6%]
Archondrite x1 [16.6%]
Archondrite x2 [16.6%]
Archondrite x3 [16.6%]

Level 6 prayer stone requires Lv 1, Lv 2, Lv 3, Lv 4, Lv 5 prayer stones, Archondrite x3 and 700,000 gold, this can result in the following:
Lv 6 Prayer Stone x1 [16.6%]
Lv 6 Prayer Stone x2 [16.6%]
Lv 6 Prayer Stone x3 [16.6%]
Archondrite x2 [16.6%]
Archondrite x3 [16.6%]
Archondrite x4 [16.6%]

Elemental Stones
You can refine x10, x50 and x100 elemental stones to receive x1, x5 and x10 of the next level. For example x50 Lv 1 fire stones will result in x5 Lv 2 fire stones.