Upload & Sell: Off
I really loved the 55-250mm IS on crop, very sharp even wide open. Only reason I sold is for full frame, I even looked up if molding it would work. It can be found for $100-150 here in SD, new or used, just be patient and test it out. It was included in a lot of kits so there cheap.
You can def find used copies of the 70-200f4 non-is for <$500. The USM is nice, but it's larger (size and weight), white (stands out more for better or worse), and lacks IS, of course. I really enjoyed it on my 5dc.
I heard good things about the Tampon 70-300 IS (or their version of Is) with image quality better than the Canon non-L but below the L. I haven't personally shot it though