Sorry about taking so long to get back to you, I have been pretty busy with work over the last couple of weeks!
First of all, don’t be scared to invest your gold into the inexpensive, low level items whilst bulk flipping. If you are buying 10’000 onions for 6 copper each then you will only be spending 6 gold, to make a profit at this price the lowest you need to sell for with fee’s is 8 copper for a 13% return in profit. If you had to sell at 7 copper, the only loss you will make is 5 silver coins (-1%).
Carrot, blueberry, onion, potato, beet & garlic are all great items to invest in bulk, and the usually have a relatively stable price and if they do fall I will personally be buying all the low prices stock anyway for when they ultimately rise again.
Now, 280 gold is a good chunk of gold and it’s unlikely you will want to invest all of this into bulk flipping materials. That is why we also flip items daily over several different markets and items to cover any loss and increase our profit potential (this is diversification).
As for making gold with your large collection of skillpoints, you should check out the brilliant spreadsheet here: