If he was given money in the summer (instead of the board selling players off; till January) then this half a season phenomenon wouldn't happen.
Thats a curiosity of the EFC board.
He knows the conditions he works with. If he needs to sell to buy, then he should sell. We've lost out on a lot of money because Moyes never sells a first teamer off his own back. We were offered big money for the likes of Saha, Yakubu, Rodwell and Jags that we could have reinvested. Wenger and Ferguson have the guts to know when a player has peaked and can be sold, Moyes doesn't. Instead we only offload players for cheap after a year of bad performances unless our hand is forced by the player in question.