Some of the prices on these lovely rifles depends on the history of the rifle in private hands, such as who commissioned the build, who it belonged to afterwards, which matches it won, etc.
For most shooters, not interested in the nostalgic aspect, the next factor as to what a fair price is for these rifles is "condition"
The first condition which should be taken into account is the condition of the throat/leade.
Some of these old girls are veterans of many practice shoots and matches.
Many have seen thousands of shots down the bores with both military issue type ammo and handloads.
So, if you're a shooter only, then look closely at the throat/leade/bore. If it's worn beyond use, which many of them are, pass.
Condition of furniture. Some of these rifles look very good, even though their barrels are shot out, many have had their barrels replaced, sometimes quite often, depending on the owner's needs.
Next, make sure the match sights are complete and working. Parts can be unobtanium.
These rifles in working, matching numbers, condition, VG to EXC bores start around $1200, depending on the economic conditions of the area.
Most folks aren't interested in anything with iron sights these days, no matter how good they are, and other than wanting to fondle them at gunshows, out of curiosity, they don't have a large niche.
That being said, there aren't a lot of them out there in the original CAL factory condition. When you find one, it may be different from the last one you saw, but that doesn't mean it's not original. These rifles could be custom ordered with several options, which didn't disqualify their use for DCRA sanctioned matches.
I've seen "modified by bubba" DCRA CAL built rifles which have had their stocks cut back, drilled and tapped for scopes, etc.
So, for complete, original rifles, anywhere from $800 to $2000 depending on the above factors.
For bubba examples, whatever the market will bear.