Benteke appears likely to leave Villa Park for Liverpool for a fee of £32.5million, and Richards believes Austin could be the ideal recruit to fill the void left by the Belgian international.
"Charlie Austin has scored a lot of goals hasn't he? I think we just need a goal scorer if we were to get rid of Christian," Richards said.
"Some of the games I watched towards the end of last season, he was winning games on his own.
"With the signings we have been linked with, it seems positive. But like anywhere, if you lose your main striker, it's always going to be tough to replace."