Potatoes - should I start again?

Never really tried growing veg before but on the spur of the moment bought some red Duke of York seed potatoes and planted them 2 weeks ago.  With glorious hindsight, having since looked at pics on-line of chitted potatoes, the sprouted bits (about 2") on mine were withered and blackened.  As we're very pushed for space, is it worth leaving them in to see what happens (currently no growth showing) or whip them out and buy/plant some more?

Don't know what made me buy them... I'm usually very fussy about what my money goes on, plant wise

Two weeks isn't an excessive length of time for shoots to appear (depends on several factors including how deep you planted them.)

The chits were obviously poor but the seeds should still be able to produce some more; I'd be more than tempted to dig one up to see what's happening, you may be pleasantly surprised, but if not at least you won't waste any more time worrying about them!  

Chits on my red DOY were very dark purple - almost black - but healthy. Are you sure the 'withered' bits weren't little leaves just starting to unfold? They do look a bit scrunched up.