How much should I spend on paint?
As with a lot of products, the more you spend on a paint, the more likely it is to be of a better quality; therefore the advice would be to spend as much as your budget allows. Remember that with the labour involved in preparing and coating a surface, it is worth spending a bit more now and having a finish that will last, than having to re-coat something sooner because a cheaper low quality coating was used. A better quality paint is also more likely to be easier to apply and coat the surface with a satisfactory finish.