The winter sale fare don't usually become available until August/September. I do believe you would be buying too early if you buy now.

If you don't want to take the risk of air fares increasing but don't want to lose out on fares going down, some airlines (namely the U.S. ones) will reissue the ticket and give you a partial credit if the fare goes down for the same, exact itinerary. Not sure if AA does this w/o a huge charge. NW does it domestically for USD 25. Not sure what the international charge would be.

If you are not stuck on AA/oneWorld, consider alternatives such as NW (codeshared on KL) LAX-AMS-MAN. It'd make for less worrisome and hassled transits.