Speak to Motoliner- they straightened one of mine.
If you are talking forged then I wouldn’t buy it,no better than cast and it won’t match the front.
If you have a non-MotorSport K1300S then it depends how much you value function over form. The forged wheels are definitely better to ride on and the most influential is the front wheel.
If I had a K1300S I'd be tempted to buy the wheel and fit it. Id' then get the benefit of the better front wheel. If (when?) the wheel gets bent on a "now standard issue for every road" pothole I could either get it fixed if it's cheap enough or bin it. The financial loss only being slightly more than the cost of a repair and the original wheel would mean the hassle-factor would be pretty low.
When it came to selling the bike I'd return the original wheel to the bike and sell the forged wheel separately for no less (probably more) than I paid for it. The only down side in all of that is riding a bike with mismatched wheels.