tick speed challenge

  var costs = [1e1, 1e3, 1e4, 1e5, 1e6, 1e8, 1e10, 1e12, 1e15];
  var buttons = [
    [$("#tickSpeed"), $("tickSpeedMax")],
    [$("#first"), $("#firstMax")],
    [$("#second"), $("#secondMax")],
    [$("#third"), $("#thirdMax")],
    [$("#fourth"), $("#fourthMax")],
    [$("#fifth"), $("#fifthMax")],
    [$("#sixth"), $("#sixthMax")],
    [$("#seventh"), $("#seventhMax")],
    [$("#eight"), $("#eightMax")]
  ];

  function preparePrice(price) {
    var regex = /Cost: ([^)].*)/;
    return price.match(regex)[1];
  }

  function checkPrices() {
    for (var i = 0, l = buttons.length; i < l; i++) {
      var safeToBuy = true;
      var verySafe = true
      var fixIt = false;
      var price = Number(preparePrice(buttons[i][0].text()));
      var nextPrice = price * costs[i];
      var nextNextPrice = price * costs[i] * costs[i];

      if (!isFinite(nextPrice)) continue;

      for (var i2 = 0, l2 = buttons.length; i2 < l2; i2++) {
        if (price == Number(preparePrice(buttons[i2][0].text())) * costs[i2]) {
          fixIt = true;
        }
        if (nextPrice == Number(preparePrice(buttons[i2][0].text()))) {
          safeToBuy = false;
        }
        if (nextNextPrice == Number(preparePrice(buttons[i2][0].text()))) {
          verySafe = false;
        }
        if (nextPrice == Number(preparePrice(buttons[i2][0].text())) * costs[i2] && i != i2) {
          verySafe = false;
        }
      }
      if (!safeToBuy) {
        if (fixIt) {
          buttons[i][0].css("background-color", "#CC0000");
        } else {
          buttons[i][0].css("background-color", "#880000");
        }
      } else if (!verySafe) {
        if (fixIt) {
          buttons[i][0].css("background-color", "#CCCC00");
        } else {
          buttons[i][0].css("background-color", "#888800");
        }
      } else {
        if (fixIt) {
          buttons[i][0].css("background-color", "#00CC00");
        } else {
          buttons[i][0].css("background-color", "#008800");
        }
      }
    }
  }

  setInterval(checkPrices, 100);

  checkPrices();