Blineboy, I finally figured out the discrepancy! I had to go look at gotvapes site to figure it out. The $37 does come with one tube compared to the $60 one, which comes with two. The $37 itaste svd only has the short tube, but it will telescope to accept 18350 or 18650. The extra tube you get with the more expensive option is more for a nicer form factor if you are using an 18650. It makes to tube a uniform diameter all down the tube, rather than having a thin-thick form that you'd get with the shorter tube. Or something like that. They call the long tube the "extended grip" tube. Look at the 11th picture on the gotvapes svd page.
I don't know if I explained that correctly, but if you look at the itaste svd kit on the gotvapes site maybe it will make more sense.