USO roll over -- money left on the table

I didn't want some of my USO assigned tomorrow so I rolled my Aug 34 calls over to Sep 34 calls. I split the ask-bid prices on a credit order (0.45) and it went through immediately at 4.30/4.75. The speed of execution and the nice round numbers mean I left money on the table... Probably could have gotten at least another 0.05.

September update
Bought Sept 34 calls and sold Oct 34 calls for net credit of .55.   I tried .60 first with no execution.   The quoted net credit was .4.   It definitely pays to do the combined orders on these and start the credit offer near the net debit side of things.