One way to afford physical comics is to set aside a specific amount of money each month for your comic collection. You can also trade comics with friends to expand your collection without spending much. And don't forget to check out local comic conventions where you might find good deals.
Well, you could look for sales and discounts. Also, buying second-hand comics can be a cheaper option. Another way is to limit your purchases and only get the ones you really want.
You can save up money from your allowance or part-time job. That's how many people do it.