I think it can be done. However, you will need a strong presence on eBay and COMC and these 2 items will probably account for a large portion of your sales.
You should have your own website and online store.
The store owners that I know have told me that the thing that keeps them in business is the high number of people coming in the store trying to sell their collections. You have an opportunity to come across some great items from walk in customers, and even buying junk year collections can be profitable if you can get them for a low price.
One thing that I see with card shops and antique stores is that their hours are posted on the door or on their website, yet when I go to the store it will be closed. Make sure you are open when you are supposed to be open, and plan on a lot of 12 hour days and 7 day work weeks.
Good luck. The best advice when I opened a store back in the 90's (not a card shop) was the formula for the amount of money that you will need to open up. The formula is : Figure out how much money you think you will need, then double that amount, and you still won't have enough.
