Yes I agree there are some much better options nowadays. I have tried Redbublle for print on demand and did sell a few things.
At the time for the postcards I did talk to. A local printer about printing them and they could not Ben come close to the price. They were asking over $1 per postcard at the time. So Vistaprint was a good deal, but there has to be better companies to work with I think. So will check out the ones you mentioned especially for the other items.