I also have the D1 and it's a great machine. I originally had the floppy version, but it became possessed one week after I bought it so the store replaced it with a USB version. I preferred the floppys honestly. The USB is much slower to load and I have to pull the USB in and out several times before the machine reads it is sitting there. Someone above me mentioned both of those issues as well. It is an older machine so computer technology has updated quite a bit. I have to keep an older XP computer around just to use the embroidery software - I have 3D...I believe Viking is up to at least 6 now.
So you need to make sure you have the software and a computer that will read it in order to use the embroidery portion. If you only end up using the sewing portion, it is still a wonderful machine. It makes beautiful stitches, have tons of stitches built in, has the automatic foot lifter which I just couldn't live without any more.
Whether or not the price is right I can't help you as I stopped looking at machines once I bought my D1. I don't have any plans to upgrade it unless it up and dies on me. I hope it works out for you and you enjoy it!