There have been a few limited-production half-frame variants of modern cameras with 1/1000 sec or faster maximum shutter speeds. Camera West currently lists a half-frame Leica M4-P for a mere $22,995. There's a Japanese seller on eBay offering a half-frame Nikon FM2 outfit at a BIN of $4000. Several Alpa reflex cameras were offered in half-frame versions, all costing in the range of a few thousand dollars when they show up these days. There was a repair shop in San Diego that used to offer affordable half-frame conversions of the Cosina SLR that was rebadged by several vendors (Nikon FM10, Yashica FX-3, Olympus OM-2000), but they stopped that service a while back, and I've never seen a used one for sale. Finally, Konica made a few FT-1 Pro Half cameras, though I've never seen one offered outside Japan.