I don't think he looks small to me. Males are naturally smaller then females. Typically males rarely reach past 3ft. They are slender snakes and are slow growers. Being 6 years old he looks healthy. As for the heat rock, she just might be uneducated and if you look at a heat rock packaging they will either have a corn snake or bearded dragon on the packaging so it can be misleading.

Also corn snakes do not need a lot of heat compared to other species of snakes. They are north American snakes and generally in the wild they would not stay in a place higher then 82F. I am not saying he should not have a heat pad of course but do not be alarmed and worry that he freezing to death. These guys also naturally burmate in the winter. They can with stand temperatures as low as 62F.

The cage looks dusty but the aspen he is sitting in looks clean. I really doubt that he is being mistreated. I wouldn't call it a rescue at this point, more like a purchase. He looks very healthy and the only things wrong is a dusty cage top and a heat rock. Not a reason to call it a rescue.

During the late spring and through the summer, it gets to be about 80-82F in my house so I turn the heat pad off in my corn snake's enclosure. She doesn't even use it during the time because it is way too hot.

$100 for her to make the hour trip, include the cage and snake, seems like a good way to go. Buying a new age for him would be $100-$200 any way and being that he is a normal morph he would cost about $20 himself depending on where you go. And I know it would take my vehicle $30 for gas on an hour trip and then there is her time wasted as well.