I don't want to be THAT guy, but I'd be a bit cautious about the material claim of the seller.
Many stainless qualities are not magnetic. In fact, it is one of the main properties of stainless steel.
Stainless is welded using Argon gas to avoid contaminating the weld.
Sometimes the welds on stainless steel will rust a bit because of the added material. Some welds, especially around the flanges look a bit rusty to me.
Lastly, the heat discoloration does not look like Ti to me.
But then again, even if it isn't Ti it is still a GREAT price for a nice set of headers in what looks to be very good shape. Get yourself a Ladybird can and you have a great system for next to nothing.