How much is my account worth?

he meant seeing the account value based on the CV formula.

But that already exists..? (Edit: Well, when SGT isn't down, it does. o.O)

CV doesn't care where you got the game either, if it's in the list it's bundled and if it's in the no-can-make-giveaway-list it just doesn't get added to the sum

CV- as in, your contributor value, the total which counts toward increasing your site level- cares very much what list the game is on. Also, free games do give normal value, they're just usually deleted by staff [thus removing their contribution].

If you're talking about that raw total that's listed on SG next to your games sent, then yeah, that's a useless stat, and it seems that any of the more long-standing or invested users ignore that value outright. It seems to be there more to titillate new users than to offer anything of more mechanical value.

Edit:

CV doesn't care where you got the game either,

It occurs to me that another interpretation of that statement exists, if you happen to be confused about how CV works:
CV doesn't retroactively change just because a game changes lists. If you give a game away [unbundled] or [bundled], it will always give you that CV, even if the game later becomes [bundled] or [free]. The only exception to that is when a game was already considered bundled/free at the time you posted it, and the game hasn't yet been updated to that list/deleted from your account.

As such, the site could give you current estimated CV value, but if the Steam API doesn't let them check against the activation date on your account, it wouldn't be able to determine the CV value as per the normal formula. And if the API does allow for that, it'd likely be more site load than cg'd be willing to dedicated to something so unnecessary. And, as I stated in the last comment, there'd be no way to get an accurate CV analysis, since it's doubtful all your games were acquired in such a way that their cost to you reliably adhered to the CV timeline of the site.

Okay, so you're not interested in any sort of precise/accurate calculation of your library value as per the CV system, just a "what would my library be valued at in CV if I won all these games here on SG, at this precise moment" calculation.

Like Wolfe mentioned, it seems a completely irrelevant statistic (which means it'll be hard finding support for its implementation).
That said, since the account calculation is already coded in, it'd presumably be very easy to copasta that function, tweak how it values now-bundled games, and have it report the adjusted value.
Still, for something that niche, it'd be more suitable for an outside resource (eg, scripts), which is generally SG's approach to covering even fundamental site elements. You may want to ask Knsys if he can add it to SGTools without too much hassle (and if he'd be willing to do so), since SGT has the same account syncing elements SG does, and so should be able to implement such a function fairly easily.