Though really doubtfull, you can look in the gaia exchange for items less than 50k (most tend to be 100k+ but there are some here-n-there).
If you do find an item, make an offer between 70% - 90% of the ABP, lower tends to be lowballing and higher than 90% is not really worth it.
Then sell it that same day at ABP.
Note: Check to see if the item is easy to sell. With me I make sure there is an average of around 5 per day being sold, but some preffer higher.You can also buy everything below Sell Back Price if it has one, then sell it back to store once it's in your inventory.
Only gets you a few gold profit but it does add up, I kept doing this until I had 100k, then started doing my first advice 1 item at a time.
Note: If you get items that have a Sell Back Price with a .5 (point 5) at the end, it rounds down. But if you sell 2 of those items AT THE SAME TIME, you get 1 extra gold due to them adding together.If you got any seasonal items, sell them the week of the appropriate season, except for the current items (ex: the xmas items your getting now, wait to sell them next xmas).
Always get all the free items you can, they can get a profit later.