As Grid infrastructures become more widely used by the academic and commercial world, the problem of resource allocation increases in complexity. Resource trading markets are one mechanism that allows many resource owners and resource consumers to trade. To perform efficiently trading markets for grids require approaches to match consumers and producers. Solutions for optimal and non-optimal resource trading exist, but fail to scale effectively to meet the challenges of large numbers of traders. This paper first defines the problem of scalable resource trading in grids before describing and evaluating greedy approaches for scalability. Keywords-heuristics, grid, trading, markets, allocation