It looks like these shoes are very similar to the Nike Roshe Run trainers. These are available on the Nike website, here:
http://store.nike.com/gb/en_gb/pd/roshe-run-shoe/pid-1471009/pgid-1533929
On the Nike site, these appear in black and white, with a small selection of different colour combinations. However, there's the option to customise the trainers to match the lime and black shoes you've shown.
These are £70, or around $115. Nike offer free delivery for offers at this price and returns are always free!
If you want to look at other similar shoes, a good way to find them without having to search loads of sites is to use Google's reverse image search service.
Just right click on the picture, select 'Search Google for this image'. Google will then show you photos similar to the one you've clicked, which can be especially helpful for shopping.
