Very unlikely you'll sell these for more than reg fee right now (and probably much less). The only 7N selling for half-decent money have really good patterns, often with 888 or better included. You'll probably be holding onto these ones for quite a long time before seeing any return (if ever).
I'm in the same boat. Only a couple weeks into domaining (in Jan-Feb of this year), I registered a dozen or so with patterns like 8080860 and 4488825. I'm waffling on whether or not I should bother renewing them next year, or just dumping them to the highest bidder.
Check Namebio to see what kind of 7N patterns are getting $100 or more. But I would say the best bet is to avoid numerics altogether until you really understand the market. It fluctuates a lot, and anything beyond 5N is quite volatile.