Maybe some screws, but I think you could get by without any spare parts.
I've owned handguns for the past 25 years and have never needed a spare part. In fact, the only think I can think of is that a buddy lost a screw out of his rifle stock during a hunting trip. Didn't effect his accuracy however.
I'd be more inclined to buy some ammo or dare I say another gun...
"He who laughs last, laughs dead." Homer Simpson