Don't be tempted by the first one you see.
There are not enough details about that one to be convincing, IMO.
It looks like an Escom AT1200, so it should
have 3.1 ROMs, but it doesn't say so. "Floppy drive replaced and working" does not sound very reassuring, hard drive size is not mentioned and "backup install disks" don't sound like original disks.
You should give that one a miss, I think.