Universal flaps are rubber.....arent cut to fit......you have to drill holes and buy fasteners. If you dont see the value in them then you wont understand pricing. By all means hit up an autostore and slap the $40 flaps on your 60k truck.
I had the RSI on my 23 F150 and I am thinking about getting it for this also. The Maxliner is my top choice though...I had an inquiry into them but they are apparently looking to see if it fits the US spec RR.