@nprofile1q... Good news is, if you're anything like me, storage sizes have way outgrown my actual needs the past decade.
If I didn't have a big image library I could do just fine with a 250GB system disk - and the images could honestly live on an external 500G spinning disk without any real trouble.
I'd go for a smaller, affordable SSD now, and perhaps upgrade if or when you really need to. Hopefully prices are a bit better by then.