Buying IP Bandwidth Across a Peering Exchange

I know typically peering exchanges are made for peering traffic between providers, but can you buy IP transit from a provider on an exchange? An example, buy a 10G port on an exchange, peer 5Gbps of traffic with multiple providers on the exchange, and buy 5Gbps of IP transit from others on the exchange? Some might ask why not get a cross connect to the provider. It is cheaper to buy an port on the exchange (which includes the cross connect to the exchange) than buy multiple cross connects. Plus we are planning on getting a wave to the exchange, and not having any physical routers or switches at the datacenter where the exchange/wave terminates at. Is this possible?