Note, it doesn't have to be an ASUS device (Media Bridge might lead some to believe it does). Any wireless ethernet bridge will do the trick. And that opens the door to all kinds of devices, be it standalone dedicated ones, or old routers that support DD-WRT, FT (FreshTomato), etc., all of which can be converted to a wireless ethernet bridge, or even a repeater bridge.
As
@L&LD suggests, sometimes you can find compatible devices at yard sales, thrift shops, etc., where ppl don't realize these older devices can still be salvaged. It's one of the reason I tend to hang on to my older networking equipment much longer than others. It comes in handy.