The League One champions are one of a host of clubs keen to sign Cox, who scored 32 goals last season, with West Bromwich Albion and Celtic also linked with the forward.
Swindon chairman Andrew Fitton has valued his star asset at around £2.5million, but Hoos believes that sum is unrealistic for a player who has yet to prove himself in the higher reaches of the Football League.
"That is pretty steep for a League One player. We know where we need to shore up but we are trying to get things done within reason," Hoos told the Swindon Advertiser.
"It is not a case of having an unlimited amount of money, market conditions are tight and we are trying to do the best we can with it."