As far as add-in graphics cards go, at work, we paid somewhere under the US$1295 (each) list price for a few Matrox Impression VLB video cards.
This was well before the existence of AGP or PCI when all you had (on X86 PCs) was VLB (VESA Local Bus, 32-bit), EISA (32-bit), and ISA (16-bit AT and/or 8-bit XT).
The Impression could do 1024x768 @ 24-bit, 1280x1024 @ 16-bit, and 1600x1200 @ 8-bit. That was 1990.
Before that, I used AT&T Truevision TARGA and VISTA graphics cards, but these were mainly for video and still-frame video. Those could cost as much as $5000 -- depending on how much expensive V-RAM you needed (the VISTA card allowed for V-RAM and an extension of D-RAM beyond 4 MB all the way up to 16 MB). That was going back to the mid-to-late 1980s.
Then, before that, I've worked with what were essntially workstations wrapped around a frame buffer, namely: Apollo/Domain, Silicon Graphics, MassComp, Evans & Sutherland, Stellar, Ardent, Stardent, CDC, AT&T, IPI, and some others that I'm sure few have heard of before. The prices for this stuff was rather formidable. A typical nVidia card of today can kill any of these at 3D.