(1) Homak HS30003607 7-gun cabinet - $45 FTF - this is the bolt-together model that Wal-Mart sold several years ago. Once assembled, it's pretty sturdy. The bolt heads are of the "security" variety that are pretty hard to unscrew without access to the nuts on the inside. Here's a stock picture and a link to the Homak site:
Mine has a few scratches, etc., but it functions like a new one, and you don't have to assemble it.

(3) Homak cabinets identical to the above, but assembled as a single unit with three locking doors - $140 FTF. I used the factory bolts and nuts to tie all three units together into a single 3-door cabinet that looks and works well. I drilled the rear of the cabinet so that the bolt holes will line up with common 16" stud spacing (a single box lines up fine, but when you gang them together, things get out of kilter). Total stated capacity is 21 long guns, with three small shelves for ammo, etc. Two keys included for two cabinets, but one key is broken for the third (so you have one function key for it). Replacement keys are $20 from Homak.
(1) Homak welded 8-gun cabinet - $65 FTF. Similar in construction to the Stack-on boxes, but with (IMO) a slightly better locking mechanism. This unit has a better shelf in it than the 7-gun units, and it's a medium brown color. Two keys included.
I'll get actual pictures up in a day or so if nobody buys these really quickly. I can deliver locally if you don't have a vehicle that can handle something like this. I'll also be in the New Plymouth area on Saturday, so delivery might be possible along the I-71 to OH-33 route that winds up going through Logan (but short of Nelsonville & Athens).