Two things worth studying. 足を運ぶ ('to go, visit,' literally 'to carry one's feet') is a compact idiom for 'making the trip' — suggesting a bit of effort or inconvenience. 手元に置いてある ('kept at hand') uses ~てある for the deliberate resulting state — someone purposefully placed the stamps there and they remain there. ~なくてもいいように combines the 'don't have to' pattern with purpose ~ように.