Do you mind listing down your stats so its easier for me to help you? You can buy eye of newts at port sarim magic store and sell them at grand exchange. Mining can make a profit too. Mine clay and turn them into soft clay. Mining is your best bet if you wanna get some levels up.
Or, buy items through the Grand Exchange knowing that the value of them will increase, and hold onto them and sell them in the future. Though, with 100k, I'm not sure if that will work out well.