Welcome to the forum. There are a number of after market speakers for the Wing. J&M comes to mind. They tend to be a bit pricy, but have great sound quality. If you do a internet search I'm sure you will come up with others. Good luck in your search and ride safe.
Factory speakers are more $$ because they are Honda, it's that simple. From comments made on other Wing forums speakers from J&M and others seem to have better sound and quality. Most are waterproof and should just mount and plug into existing location. I've never had to replace speakers on my bikes but there a lot of folks who have. Biggest thing is taking off the covers and putting back on properly.
I'm sure others will chime in on this for you. Good luck and ride safe.
Two Wheel is right on that. The hardest part is the removal of the grilles and the associated fairing peices. If you don't have a shop manual get one, there was a post somehere on this forum about downloadable pdf manuals, and I even think they were free. Go to Wingstuff, they have lots of options for speakers if I remember right.
This may be off your subject in a way , but I do have a question for the group. Back on my 2003 GL 1800 it seemed to me the volum automaticly rose with the speed of the bike (I think ?) Now my 2010 does not do this and I must use head set or jack up the volume to like 26 to hear it , in turn this May blow the speakers ?? Question, am I missing setting a sound controll or do these Wings no longer have auto volum ?