i dont know about the cheapest one but the belkin wireless routers are cheap and very good in quality.i myself use one of them.i think you will only need upto g standard router(about 1k) and a g standard reciever(about 600 bucks).anything less than what i have mentioned is going to be sub-par in performance.and if your only use is surfing on your smartphone then don't get the receiver and connect your pc with the router using a Ethernet cable as the router also has 4 Ethernet ports.its pretty easy to set up and you will be up in no time.if you are wondering about the exact model number,you only need to ask for belkin's g wireless router(F5D7234-4-H V5).