It's on the low side, but might just run fine for a while. Get it, run it, and collect the knowledge and parts to do the job while you're using the saw. It's not a hard job at all. I personally am not crazy about just reringing the piston unless you make sure the piston is not excessively worn... it's not always simple to tell by eye. The good news is that a decent aftermarket piston is 35 bucks.
If you let a piston run too long, even on a well-cared for saw, you run a risk of snapping the piston skirts. That can be expensive. If you have a good set of calipers, you can measure the piston up well enough, and maybe you can get away with rings.