It is not too late to do a very serviceable Ness impersonation this Halloween, thanks to Fangamer, creators of the Earthbound inspired "Awesomeness Combo Pack," complete with shirtness, hatness and yo-yo-ness.
Like most things Fangamer made—the Mother 3 Handbook, for example, or their sundry t-shirts—this Earthbound-ish get up comes with any number of unique pins, adding additional flair to your Ness cosplaying. There are even ultra-rare pack ins that might net the lucky Earthbound/Mother enthusiast a special yo-yo or badge. On top of that, Fangamer is offering your choice of hat embroidery, further making the combo pack uniquely yours.
There are men and women's sizes of the Awesomeness Combo Pack, both priced at $54. (But there does appear to be some discrepancy about the pre-Halloween availability of the thing. The site says you can rush order a pack as late as Tuesday night, but the rush shipping option appears to be unavailable. Act accordingly!)
Awesomeness Combo Pack [Fan Gamer]