The loss of his house didn't have enough impact imo. It IS a reason to feel like shit, but it wasn't well written. They had to show us more about his hard work toward that house and all. It all felt generic (even if it isn't) when reading.
About the auction, he really should have started with like, a third of the price. Starting with 50k when no one wants it and slowly raising till reaching middle ground with the seller is how you do it. I know MC is no merchant, but he said he took many side jobs and put some aside money for himself, to me he had the how2basic of bidding.
Original story, graphics are ok (I've seen worse honestly), but storytelling to improve.
Also WTF Mario is a slave merchant?!