Hi Albertt, It means that some people pass up opportunities because these opportunities seem to involve too much hard work. "Overalls" is used as a metaphor here as it refers to a loose-fitting garment worn over ordinary clothes for protection against dirt. People wear overalls for protection during manual labour (e.g. farmers) though they have become fashionable pieces too. "...it (the opportunity) is dressed in (is packaged) in overalls (in a way that seem to involve too much trouble or hard work)." I hope this helps you.