Originally Posted by
bankingconsultant
Another way I've done it in the past is to buy a one-way ticket for the first Monday from NYC, then buy Friday-Monday roundtrip tix ORD-NYC-ORD, then buy either a one-way (or a roundtrip and throw away the return) for the last Friday.
This is exactly what I was encouraged to do when I was consulting (back and forth between ORD and NYC, actually), but I found that it wasn't any cheaper to book tickets like this vs. without the Saturday night stay (as the OP himself has discovered).
Book as early as possible, and make sure you consider EWR as a start-/ end-point, unless it is ridiculously inconvenient to get there, as oftentimes the ORD-EWR tickets were a little cheaper than ORD-LGA.