Crowdsale is the best time to buy coins because the price is usually lower than it will be after the coin launches. This is a great opportunity to get in on a new coin at a lower price and then watch the price go up as more people learn about it and start buying it.
Buying $MTC now will help you generate good returns in future. It will be also very useful in the Martell ecosystem. Additionally, since Martell trading platform is just around the corner, trading with MTC will be rewarding for holders and investors.