Certain NPC allow you to sell them divine seeds. They sell for 150 G each, make sure you check your achievements in the teleport area to see if you can get extra ones.
The easiest way to get money is to just go to the debug room and spawn in an infinite amount of gold.
Alternatively you can use growth while on a healing pad for the MP regeneration in order to produce an infinite amount of divine seeds therefore an infinite amount of gold.
