I had to call them when I last dealt with them. A lot of places were like that.
What I liked about Port was their combination of low price and small orders. Other companies beat their price but would only sell a full pallet of material. For expanded PVC they had the cheapest price I could find without ordering the full pallet.
But that was also determined by the fact that I live in an area that is expensive to ship to. If you live near more major metropolitan areas it will be worth it to shop around as shipping costs, which are huge, may be much better even if you have to pay a bit more per sheet.
A lot has happened to both shipping and plastics prices in the last two years. My advice may be totally irrelevant.
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Currently keeping a small collection of various Gonyosoma. Both G. janseni and G. oxycephala.