Looking at the numbers, I'd go with the monthly pass as well, at least in most months. It might make sense if you're going on a long vacation at Christmas or in the summer to skip the pass and do "normal" or multi-ride tickets for that month, but assuming that you can get a monthly ticket for $930 or so (which would be a good deal), you should rack up status.
Assuming you did ten monthly tickets at $930/month, you'd have 18,600 TQPs; incidental travel in the other two months ought to be enough to put you over the 20,000 needed for SE+, with its 100% point bonus and extra upgrade cards.
He won't be able to apply discounts to the Monthly Passes or 10-trip tickets......14-day fares, plus the 250$ reimbursement are his best/cheapest shot.....1080 - 250$ = 830$.....
I know the point has been made about specific trains; there's also the fact that the 14-day fares aren't
always available (for example, right now on June 17, there are five Regionals not at $36 NYP-PHL).
Edit: There's a possible marginal advantage to the single-ride tickets (namely, the extra AGR points). Still, there's an element of gambling there, and it's quite possible to think of days when a "replacement" ticket might simply not be available for several hours if a train is missed.