yeah this is true. Although its not ideal to use such a big tub for such a young snake who probably isnt that big, this is STILL an amazing deal.
That rack with the tubs, heat, and shipping is around $225 brand new. Your saving over $100 and if its in good shape, that's an awesome deal.
You can probably fill the tub with small items like fake plants, 2 hides instead of 1, a slightly larger water dish than normal, ect, ect and it will be fine.
I have a late 09 pastel myself, and he isn't very big at all. I keep him in a 20 gallon long tank, which is basically too large for him, but I packed it nice with quite a lot of fake plants and fake hides, and pieces of driftwood so that he wont feel out in the open all the time.
Using something slightly too large isn't a big deal. He will grow to size before you know it anyway
In my opinion its always better to have an enclosure that is a little big too big instead of a little bit too small.
Go for it man.... its a good deal