It sounds like you haven't done digital photography in a while... File sizes are much larger than your "generous" estimates--if you have a Nikon D800 your RAW images come off the card north of 75MB (over an order of magnitude greater than your estimate). You do get a ton of resolution for that (7,360x4,912), but those files add up quickly. That would be 1,638 photos or less than 5 a day.
That's shooting one frame at a time, if you're bracketing or capturing sports, you'll be shooting many frames a second and the math gets all that more complicated. Of course you can delete photos, but it's extremely easy to fill hundreds of gigabytes even keeping only your best shots.
That's shooting one frame at a time, if you're bracketing or capturing sports, you'll be shooting many frames a second and the math gets all that more complicated. Of course you can delete photos, but it's extremely easy to fill hundreds of gigabytes even keeping only your best shots.