A little more directed toward your original question: NW into SJU is hard because they don't offer many flights: I believe DTW and MSP flights are weekends only, although MEM is running daily. CO has a number of flights from EWR, but some leave in the morning; it will be hard to fly into EWR early enough to connect. CO has another IAH-SJU flight that may work for you.

Those dates are darn close to Easter, so I doubt seats will open later. Last year, CO offered CLE-SJU but I don't know if it was profitable. That may be another route to check.
Thinking of the ATA option I mentioned before, you could possibly fly ATA there and route yourself like so: MSP to MDW $128 round trip; MDW-MIA $148 RT; MIA-SJU $148 RT. Make sure you book each part as an independent round trip for them to count as separate trips for the promotion.

That's about $424 round trip for confirmed seats, and you will receive a free ticket for a future trip on ATA. That may be better than the 3 trips to Chicago to receive the SJU ticket. Plus, you save 35,000 from the NW tickets.

Not to advertise for ATA (I've been CO/NW elite for years, but ATA has better prices/schedules for my mom who commutes regularly MSP-Chicago), but it may be worth a look. Their site is www.ata.com

Good luck!

[This message has been edited by Viajero Joven (edited 01-03-2002).]