I just looked at the Epson web site. The 13000 model is not being offered now. The 12000 now has the LED light source. The Graphics Arts model is @ $2850, and the Photo Model is @ $3450. I did not see a link for refurbished units. There is a phone # 800-463-7766 that you could ask about that. It could be that the photo model includes a top light unit for transparencies that the GR Arts doesn't. I'm guessing here.
They mention a dust and scratch function but no mention of Inferred Channel, which will only work on transparencies anyways. They may be referring to the SDRx function in SF8. The SF8 SRDx function is very useful, but you can only run it once while working within the SF8 scan software. LSI.com, SilverFast, has a SRDx plug-in for Photoshop. It costs $50 if I remember right. It is super functional because you can run it many times targeting from small to larger deficit removal, using a new layer each run.
If you buy one use the SF8 software. Can be a long learning curve. It retails at about $500.