As you navigate the Shop you'll see that there are two different ways to buy shoes. Shoes can be purchased with normal Aglet (these have prices in blue) and with Gold Aglet (with prices in gold).
Some players take the approach to grind and earn Aglet, some choose to pay to play instead. It's your choice which strategy you choose (or perhaps you may choose a mixture of both?).
It's totally your choice as to how you play the game. Strategy is a very important element of how Aglet should be played if you want the very best heat.