That's a hard one. Ricardo on this board is with Lo Scarabeo and might be able to list figures if you PM him, I'm not sure he's looked at this thread.
Or you can email Robin Wood and ask her about what the first production run count was on her deck when it was released back in the 1990's, she'd give you an answer (she's very nice).
But I'm not sure how relavant the numbers would be to self publishing--on the one hand you've got a big publisher who advertises world-wide, looking at sales figures coming in from a number of countries, and on the other hand you've got someone in small town USA (or equivelant) going down to the local printer for a print run. The market varies per deck.
Mr. Rosales who did the Hello Kitty deck didn't push his, it was done as a lark & tapped into the Hello Kitty collectors group as well as the tarot group, so he just makes up decks as the requests come in.
The Tarot of the Crone had a limited run with word gone out & when they're gone, they're gone. The Mary-el tarot is working it the same way with the majors only deck that she just put out.
Then again, you get the occasional deck with all the bells & whistles done up really well with a printer willing to go the extra mile, with a lot of fanfare, like the one baba-prague is putting out, where pre-orders roll in and they can set the numbers based on response in the past 6 months.
But most artist done decks fall into the 'I've got it, maybe you heard about it but maybe not' category, which means you print up as many as you can afford to and then work at getting others to be aware of what you have. Sales depend on who likes the art, if someone collects decks specifically like yours, if people want to use it as a gift to someone, and a large number of other buying factors (most of which is out of your control). A cat deck sells to cat lovers and owners as well as tarot readers for instance. A deck based on Egypt draws in those who like ancient Egypt. Multi-marketing slants sure do help. If your deck is based on only 'tarot' you'd have the best luck aiming at tarot users and tarot collectors.
What is affordable varies per individual though. Spending $5 per deck to get it printed & cut means 100 decks will be $500 out of pocket expenses, plus shipping once they're sold. If you can get 300 printed up, that's a good run to start if you don't know what the demand will be. Or then again, maybe starting with only 50 decks might be more feasable. Larger print runs get you the benefit of a discount from the printer. You'd have to factor in the costs. You'd need to buy or find something to ship all the decks in (packaging) and mailing tape costs money, postage, are you doing up a box for the decks or mailing them out in zip lock bags? Cost doesn't stop right at the end of the printing of the deck. Will you do up a drawstring bag for each deck? Then there's fabric costs, the drawstring (and beads?) and sewing time to factor in. (Hint: always buy on sale, never pay retail).
(I hope I'm not getting long winded here...I do think it's feasable to do a self published deck & to sell them all). One place to offer versions of the art you do, that doesn't cost you anything till an item is sold is to think of t-shirt designs/coffee mugs/etc. and get a free account over at
www.CafePress.com That way you have perepheral 'extras' that can make you money without out of pocket expenses, the costs come out of the price you set for the item and nothing is manufactured in advance. It's orders come/orders filled.