Chainsaw Repair

New piston and try to clean up the cylinder. You'll need to sort out why it failed (scored cylinde) before putting it back together.

Looks more like it got hot and lean.  Maybe an air leak somewhere and/or being tuned too lean on the H side.  Like Adam said, you'll need to clean the aluminum transfer out of the cylinder.  There are a couple threads here covering that subject.  Cylinder plating may be damaged too, but you won't be able to be sure about that until you clean it up.  This may be more of a project than you want to take on at this point....

Let me ask? Anyone here sell parts? Seems like I have seen threads here where some of you had stores. I need to consider either am I gonna try and fix it or sell it to put toward another saw. One thing is for sure is that I need to be cutting wood. I have been investigating online and I am a little confused. I am looking up " PISTON ASSY    Part# 503662001 " and looking from ebay to not ebay. I am finding such a wide price range. Like http://www.ebay.com/itm/380197294857?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT to this http://www.ereplacementparts.com/piston-assy-p-620220.html , I know there are bargains to be had but I know just because it seems to be a good price it doesn't mean it is a bargain.

I know you guys on this site have been very good answering questions for me and helping me along back when I was working on the carb last year. So I should consider if I decide to try the repair and someone here has a store then look at getting the part from someone here if I can work out a decent enough price. Seems to me to be the fair thing. So can anyone here suggest a member they trust that I may contact or if not then suggest a quality location for the part.
I have trusted the members here with getting me this far.

Check out the where to buy online area below.  Lot of members and  dealers have stores there.

A couple of things to ponder. I would suggest a pressure/vacuum test before tearing it down, this will pinpoint an air leak before throwing new parts at it and having the same thing happen. You have a lot of sawdust just waiting to fall into the crankcase and necessitate a complete teardown.
The position of the scoring suggests to me the possibility of a cold start seizure. Did somebody pin it without waiting for the engine to warm up?