Personally, I love how traditional work looks a lot of the time, especially when it comes to different types of colouring and shading. I also really like that a traditional piece will feel much more "for you" as a commissioner.

Like, with a digital one, it's kinda drawn for ya, but anyone can save it and such. x3 Traditional there's that one original and it's "for you" if that makes sense? And even if you run it through a scanner/copier it's not gonna be the exact same.

Granted I'd say if you offer to ship originals there'd be an extra fee. o: The fee can help out with making sure the piece actually gets there instead of getting lost in the mail and such (which does happen and it sucks :c).

If I were buying a traditional commission, I would absolutely want the original.

As for which I'd prefer to buy, eh. Depends completely on the artist's work. Some folks I like their digital stuff better, others their traditional. I might be slightly biased towards digital work because that's how I primarily work and I like the way it looks, and as there's no real materials fee, it tends to be a little cheaper. But if an artist is clearly more comfortable with traditional stuff and their traditional stuff is awesome, I'd get something traditional.

It'd be cool if there were a 'buy a print!' option for digital commissions for an extra fee or something. I know not everyone knows how to set up for that though. (Hell, I'm not even sure where to get a nice archival print done, but I haven't done the research.)

Honestly? I'd offer both as options and price each appropriately to how long you believe it will take you along with examples of both. That way people can pick which they would prefer and would be paying appropriate to the time it will take you. If they feel that a higher price for one or the other is not something they wish to pay then they don't have to go for that option.

For traditional I would offer a digital scan of the original with the option of getting the physical original for a shipping fee (this also lets you include different fees for North America, South America, Europe, and elsewhere). Most people will understand that it is going to cost you something to ship it, especially if you're shipping outside of your home country. It also lets you do offers where if you're doing pieces shortly before a con you can offer to let people collect it from you at the con for no shipping fee (as, yanno, you're not actually shipping it) as long as they give you a way of contacting them at the con to arrange it's collection.

If you're going to offer prints of commissions for sale to anyone and everyone I would make this as clear as possible to the commissioner as for some people their 'sona is deeply personal to them. Some people contain it as a generic small-print line hidden in the middle of their ToS which sometimes is difficult to find. I would suggest including this information or the question regarding whether you can in an email to the person commissioning you and state whether a lack of response will be counted as a "yes, you may" or a "no, please don't".