Waaaaay back when I was just a young whippersnapper I took on a Burmese with only 1 eye and it wasn't a problem. If anything, I think it made her more mellow than most other Burms because she had to take things in stride. It certainly didn't affect her hunting ability - she was straight as an arrow in that department.
The eye image is hard to judge because of it's poor quality, but that's quite likely on purpose. For the price it may be worth the trip to take a look at it, but I wouldn't commit until seeing it in person. If the eye looks like it's infected or something when you get there, just tell him No Thanks, You've Misrepresented The Snake Because It's Clearly Not Healed and there's nothing he can do except get angry with himself for lying, but then again, the majority of breeders don't really have issues with that, lol.
If it's in good shape and there are clearly no current issues with the snake's eye, you've got a good deal and taken on something that clearly needed a better home than it had.
As for the general look of the snake, it looks like it could use a couple of good-sized meals and I'd be happy to see it off of those shavings. I personally think shaving and snakes are a
really bad idea, but hey, whaddo I know