Sorry OP but no I wouldn't buy them personally, it's more that it does look like fairly cheap starting products purchased from £land or hobby craft etc (the plates, the mini easels) that have been drawn on. It's not a comment on the ability (which is sound) so much as the starting quality. Re: the plates I think the motif's need to be precisely central also. I'd also not want non matching plates to the rest of the service anyway, so it's not my bag. The nordic designs are very nice and the trees are pretty.
I see no reason why you can't set up an Etsy/Folksy or sell them on ebay? It's not for 'proper' artists at all, there's all sorts on there to be honest and it takes an age to get off the ground so you may as well start if you really want to have a decent crack at it. What's the worst that could happen!
I really would work on the alignment though, I think that would cause you potential problems when selling (returns etc). If I purchased something made to order and it arrived as such I would return it.
Perhaps framed prints (on good quality paper, in good quality frames, charged at a higher price) might work.
I would factor in your time into the price, no idea how long one takes but would you even be making money? Work out how plates a pen lasts vs the cost of it, the cost of the plate, petrol or postage etc involved in acquiring it, your own post and packaging costs- you don't want to end up costing yourself money. I'd be inclined to see how it goes on facebook and then build up stock for next xmas and do the craft markets if it's a serious gesture.