I don't think it's that bad, if I recall correctly it's about 8 kilobytes per token, and a token can be 3-4 characters so you're talking ~2 kilobytes per character.

An image token I recall is something like 16x16, so you get 32 bytes of overhead per pixel. And a character is minimally like 20 pixels including the whitespace, so you've jumped from 4 characters per token to maybe 12.

So 3x savings... which actually maps pretty closely to 60% savings.