I have an 8-string Mele long-neck tenor that's tuned like a baritone. When I was at Mele on Maui in October 2012, they had an 8-string baritone on site, but someone had asked for it to be set aside, so I bought the longneck tenor instead. On the same trip, I found a rare Kamaka 8-string baritone at The Ukulele Site (aka HMS) in Haleiwa and bought it on the spot. I heard that Kamaka makes them from time to time, but they are rare (although I've met someone else in the Bay Area who has one!). Kanile'a had 8 string baritones listed on its website at one time, but I don't see them there now. Whether any of these are affordable depends on what you mean by affordable. (My Kamaka was almost $1,500, I think). Of the three manufacturers, the Mele was by far the least expensive, and my Mele 8-string longneck tenor sounds great. There are none listen on the Mele website at the moment, but someone there may be able to help you if you contact them.