To be fair, anything more than ~$250/mo probably requires some kind budget approval which will quickly scare away many underlings, and means now you're in the realm of enterprise sales. Now you should probably be charging closer to $10k/mo just to deal with that headache. It's another reason why having 3 tiered pricing can really help, with a 4th tier being "contact us for enterprise solutions". It can allow you to sneak past some of these organizational hurdles, by allowing people to select the price that will cause them the least headache. Joel Spolsky talks about this a lot, how there are holes in the market for pricing due to these frictions.
Yes, very good point. Generally, the higher the pricing, the longer the sales cycle. That can mean months of evals, potential customer hand-holding, pre-sales support, etc. In the end, someone in the decision chain at the prospect decides to go a different way and you've blown months and many dollars on trying to land the client. A small or one-man operation is not going to survive that kind of abuse and make no mistake, some larger customers will take advantage.