The Scottish international has been strongly linked with a move to Aston Villa in recent weeks.
Villa have made bids of £2.5million and £3.5million for the playmaker, while recently signing Sunderland striker Darren Bent in a deal that could rise to £24million.
Holloway told Sky Sports News, when asked what he thought Adam is worth: “I don’t know – £46million? – because if we stay up that’s what we’ll get. How important is he to us?
“So, what’s realistic to you? The fact that we might get £90m already and then we can get another 46?
“I’m just looking at the business side of things thinking ‘well hang on a minute, aren’t we doing well’.
“Charlie might look at himself, but I still think he’s doing well. He’s playing for a team that’s really good, expected nothing, he’s passing it, it suits him, the lads like him, the fans like him, so good luck and well done.
“Obviously Aston Villa are a massive club, but how can they rate Darren Bent at that sort of figure and offer me that for Charlie?”
“I think it is quite derisory.”
Holloway insists that he will not be selling Adam in the January transfer window.
He said: “No – why should I?
“The thing is, if someone offered the ‘right’ amount of money, which would be fair in terms of the market value of Charlie, how do I work out what that market value is when clubs are paying absolutely ludicrous amounts of money for people I don’t see as being as good as Charlie?
“I had a contract (as manager) at Plymouth, I left it and I won’t do that again – I learned from making that mistake.
“Charlie has signed a contract and someone can come in all they like, but it’s not his choice and it’s not their choice. He belongs to us and he is contracted for 18 months.
“You have to behave with respect and not all players do that sometimes, but that is the way the game is.
“I think he is still improving, I think he belongs to us and if someone wants to offer money, I think they are wasting their time because we don’t need to sell him at the moment.”
