Currently for the keys, I find them quite OP for the money price. You can easily spend 25$, and get 15 keys. My problem with this is that currently it makes it look pay to win, now here is my reason to back that up. (Cost:http://imgur.com/2VzLKFD) There is a 25% chance for 300,000$, 20% chance for 350,000$, and 15% chance for 400,000$. That rounds to 60% chance out of 300% total in there meaning every 1/5 keys can give you money. (Percentage of 400k: http://imgur.com/U1Slch8) Now if you look at the Baltop, Jzip is currently leader with 481,770$, and this shows with 1 key someone could easily get only 80,000$ behind the leader of baltop, and if they bought 15 keys, there is a huge chance of getting over 1 million, and doubling the baltop leader. (Baltop: http://imgur.com/tmLy3R0) Basically showing, you could easily buy your way to the top.
The thing is with the new economy one mill is hardly anything your only half way their when trying to buy a IG Spawner and of cause if people buy crates keys theirs a percentage that they will soon overtake Baltop but I have not seen one island yet which has built a money making farm eg. Cactus also the server has only been open for two days from the reset so /Baltop isn't very high to begin with
Not OP but one million In Skyblock is hardly anything once you get a decent farm setup, When my farms setup on Skyblock, I should make 5Million a day AFK'ing