Firstly, closing costs and fees vary depending on different factors, including the location of the property, the sales price, and the specific closing costs associated with the sale. It is possible that your brother's estimate of $40,000 is accurate, but it is also possible that the actual amount could be lower or higher than that. It would be best to obtain an itemized list of closing costs and fees from your broker or real estate attorney to get a better idea of the expenses involved.

Secondly, it is true that the quality of marketing materials, such as photos and listing descriptions, can significantly impact the sale of a property. If you are not satisfied with your current broker's performance, you have the right to terminate the agency contract and find a new broker or market the property on your own.

Thirdly, while it is possible to sell to a wholesaler for a lower price, it is essential to consider the long-term financial implications. Selling to a wholesaler for $300,000 means that you are taking a loss of $50,000 compared to the initial asking price. Moreover, selling to a wholesaler means that you may miss out on potential profit from a higher selling price if the market improves.

Lastly, the seller is responsible for paying closing costs because they are the ones selling the property. The costs include various fees, such as title insurance, transfer taxes, attorney fees, and appraisal fees. As for the market dropping, real estate markets can be unpredictable, and fluctuations in prices are not uncommon. However, a recent sale of a similar property for almost $400,000 is an encouraging sign that your property may still have a high market value.

In conclusion, it is essential to carefully weigh the pros and cons of selling to a wholesaler and terminating your current broker contract. Before making any decisions, I recommend discussing your concerns with your brother and consulting with a trusted real estate attorney or financial advisor.