NIKE is part of eBay's Vero Program. I think as long as you don't offer worldwide postage, or use any photos from their website (take your own photos and use only those), then you can probably sell them.

Taken from the NIKE Vero page:

It is legal to re-sell a genuine Nike product that you purchased, in its original, unaltered form in the territory in which you bought it and you may use NIKE trademarks to describe such items.  However, you should be aware that selling outside the territory in which you bought the item can be risky as certain countries and territories have laws prohibiting unapproved parallel trading.  For example, items offered for sale to European countries which have not first been put on the market by Nike within the European Economic Area ("EEA") by Nike may infringe Nike's rights.  Please refer to nikeuk About Me page for further information. 

You can read the rest of it here http://vero.ebay.com/vero/nikeinc