If WI is anything like PA in real estate sales, list with a realtor. Not only for security reasons, but transactions, inspections, and mortgages are very complicated these days.
The seller ultimately makes the listing price decision. Some agents will turn away over priced listings, others will accept them to get potential buyers. I am to the point that I try to get a document acknowledging that Ibelieve the property is being marketed above market value. That way when I am accused of not being honest, I have documentation to show otherwise.
We are independent contractors and have different opinions of how a property should show on the internet. Unfortunately, we are not allowed to post pictures of another agent's property. The seller alone gives that broker permission to do so.
Zillow is a great tool for finding property but it doesn't update their listings either.
Taxes are based on your assessed value. The new owner might have adjusted taxes if that is how your area is set up but you have to pay what the tax card says. If it had a lower assessed value, you might have been able to appeal your taxes prior to the sale.