* @param endPrice
	 * @param fixedPrice
	 * @param variablePricePercent
	 * @return false if step collides with existing step
	 */
	public boolean createStep(double startPrice, double endPrice, double fixedPrice, double variablePricePercent) {
		boolean collision = false;
		for(Step s: allPriceSteps) {
			if( ( (startPrice <= s.getStartPrice()) && (endPrice > s.getStartPrice()) ) || ( (startPrice < s.getEndPrice()) && (endPrice >= s.getEndPrice()) ) ) {
				collision = true;
				break;
			}
		}
		if(collision) {
			return false;
		} else {
			Step newStep = new Step(startPrice, endPrice, fixedPrice, variablePricePercent);
			allPriceSteps.add(newStep);
			return true;
		}
	}