I would only sell the point if you see a loomed item on the market you wish to buy with the money. There is a KAS for 350K at the moment, but 15 STR won't be much fun with the KAS.
The KAS (Knightly arming sword) is indeed a good 1H sword.
IMO the best sword if you play 1H cav and also want to be good with the same sword on foot, which is not the case with the longer arabian cavalry sword.
Picking up a cheap +1/+2 item is good if you plan on keeping the weapon and heirloom it yourself later on.
/Owner of a +3 KAS