Gets tricky tho if you want to jailbreak while you still have the device, since the itunes restore is the only reliable way (for sale) to cleanup after ur done. There is something called SemiRestore, which can bring you back to clean 'Hello' screen while keeping the jailbreak, but its risky & considered a last option type of thing. But hey if you want to explore these give it a shot & if SemiRestore (or guess I-Rat is another option) does work then you'll have more choices until you want to sell- particularly if you would like to jb in the meantime.
Heads up tho if something goes wrong (which can happen with any non-itunes restore) then you'll need to default back & restore 8.1 thru itunes & the window on that closes soon. Bottom line- now is the time to explore if you like. All the best