New to the hobby, would like some advice on what to look for when purchasing freight cars. When I visit the local model train shop, it is stocked with a bewildering asortment of brands and lines and types. Most of the stuff is shelved and in the boxes so I can't get an intimate peek at what lies within. And how do I differentiate quality from the not-so-good? Any advice on the following is welcomed: Trucks... metal or plastic? What type of couplers? Wheels... metal or plastic? Kits vs Ready-to-Roll? What distinguishes a "nice" car from a "shabby" car? In other words, what should I be looking for? Any recommendations on brands and marketing lines? What kind of price should I be expecting to pay for a nicely detailed and smoothly operating piece? I bought a couple of Proto2000 tank car kits to tinker around with for the next several days. Wish me luck!