I've got the Alpen 15-30X45 spotter. Got is last year and have used it three times, but I'm very happy with it. I was leary at first, but decided for the price it was worth a try. I'm pleased with it so far. I think I got it for about $115 on Ebay.
You get what you pay for in optics. I have a pair of Zeiss Classic 10X40 that I use all the time, way more than the spotter. Buy the best you can afford, you won't regret it.
RockyMtnOyster