The agent probably just forgot to reduce it on this site. This is not a "live" site. When there is new listings or price changes, you have to physcially change them yourself.
Americorp Real Estate
Brokers Associate, e-PRO
There may have been a price decrease that has not found it way to Trulia. The change process can take time. Our recommendation is to go with the lower price.
Any Oak Lawn area agent will be able to provide you with the accurate information you are seeking.