First question.....is your P226 a 9mm?
Second question if your P226 is a 9mm.....why would you want to sell a pistol(P226 9mm) which has time and time again passed extended and abusive law enforcement and military testing which included the DOA testing of 1982, the FBI trials of 1993, the DHS trials of 2002, and the DOD trials of 2005 for a pistol(P220 .45acp) that hasn't passed any such trials? In fact, during the DOD trials of 2005, three of the five P220s started breaking parts before they even reached 3000rds. FLETC(Federal Law Enforcement Training Center) processes hundreds of Sig pistols each year for maintenance and repair for the various Federal agencies that use them. They report that the P220 suffers almost 10 times the number of parts breakages than the 9mm versions do. Why does the P220 have such problems?...because it started as a 9mm pistol. When converted to .45acp, it was kept with the same external dimensions as its 9mm parent in order to share a common holster. However, this made the pistol relatively weak. The slide mass is also too light resulting in added pounding on the frame and frame internals causing fatigue and loss of toughness. Common problems with the P220 .45acp are broken trigger bars, cracking frames, broken trigger return springs, broken extractors, broken ejectors, and cracked slides.
If you MUST have the P220 .45acp, for God's sake don't give up your P226 to get it.