There are many ways. The quicker, the higher the risk, as said by the others, the quickest is to gamble. Next to it is through trading but for me this is the hardest since it's going to require you patience, analysis and right decision making. The other way is to buy as many as you can until you reach 1000 xrp. Another that I think is through working for it, like offering a service and the salary you get there is either the whole amount you'll buy is for xrp or just a part of it. There are many that you can think of it, from low risk to the highest risk. But if that's your goal, I'd go for the lower risk, slowly yet a very sure method.