Hi there. I used to get my textile artworks photographed by my printer, who charged for this but now I photograph them myself and upload them to his site. He then sets out the artwork, for which there is another charge, and then prints out the cards and prints on his commercial printing press. He uses very heavy paper for the prints (they are almost like card) and giclee printing (which is just a term for the inks he uses i.e. archival inks which do not fade over a long period).
I couldn’t make that investment myself for the kind of printer he has, and although I have got a good stock of cards and prints at home, I’ve not been left with dead stock. I also appreciate the graphic design service that comes with it, which I wouldn’t be confident about myself!
I also think it depends on what type of cards you are planning to sell - whether you want the ‘proper’ hand made cards (in which case buying card stock and gluing or taping things on is the only way to go), or reproducing art onto the cards.
Google a couple of local printers and just phone them and have a chat. You’ll be amazed at how helpful people are and the more you talk to them, the more hints and tips you’ll discover, which will help you make your mind up.
Having a workaround by combining printing things and then sticking them onto card might work out cheaper in pure cost terms but also consider how much time it would take you to do that yourself. You’d still need equipment for cutting etc, so if you paid a commercial printer a bit more, but saved yourself lots of effort, it could be worth it. But equally, having a workaround could be good to test the market and try out some low volumes of different designs and see what works/ sells best for you.
All the best! 