There is no barometer to measure replay value. It's incredibly subjective. It all depends on the player. If you want to beat the game once, then that's all you get from it. I still remember having to beat the original MGS 3 times to get multiple endings with different secret items like the stealth camo, bandana, or tuxedo.
I bought Call of Duty: Black Ops the week it came out and didn't play it longer than a month because I thought the game was buns. Didn't even touch the single player. I bought it for multi-player and barely played it. To me, if a single player game is done right, it has a lot of replayability. Every game has replay value to someone if they find it compelling enough to play it again.