I bought the swiss gear poles with exactly that thought in mind. It would seem that all poles "work" the same in terms of how you can use them while you hike. The more expensive poles just "work" longer, i.e. are less prone to breakage. So if the cheapies last for a few trips and help you decide if you want to spend the $110+ on top notch poles then they are well worth the $15 to $20 that Walmart charges.

The top quality poles are lighter of course. But there's a problem with wanting the lightest right away anyway. The lightest poles (like the ones at Gossamer Gear or Backpacking LIght) are not adjustable. You buy them custom cut to your ideal length. But how do you know your ideal length? Once again $15 and a little experience with Walmart poles will help you determine that.

Other people may have other ideas of course. In particular some people adjust their poles for the terrain (uphill or downhill). Way too much work for me I'm finding. One length is fine for me.