Below: My alternatives to the Ae Deep-V Slub Henley. Obviously the first shirt looks way closer than the second one... The first shirt is by Rue 21, and is almost identical to Bella's, while the second shirt is by Aeropostale, and is a cheap alternative. Both shirts were purchased from ebay. The Aeropostale shirt was less than 1/3 of the price of the Rue 21 shirt.
Below: Bella wears the Ae Deep-V Slub Henley over a long sleeve thermal in New Moon when she tries to "cliff dive".