I am personally not very optimistic here..the name has low, standard renewal for .rocks, but this is not a strong new gTLD combo...which means that end user can go for tons of alternatives in new gTLD space if they want to express this, or slighly similar idea...and when there are tons of alternatives, there is no way to achieve a significant profit for domain investor.
This is the reason I feel this is not going to be very profitable, if at all.