I also had a big problem with this. When the 470w was out, I kept losing to used Xerox's and OCE digital systems. So the 240w came out and I thought I had it made. Wrong. My competition was selling their product AND 240w systems...often at a lesser costs than mine.
Being honest, I got pissed. However, I just accepted that new rules were now in play. Instead of blaming everyone else for this "unfair practice", I just developed a new strategy. It didn't work for every sale, but if you have some advantages, let the customer know this. Label them as popular misconceptions that many people have about wide format. Most customers really do not see a difference in system or companies because it hasn't been proven to them. And it is sad to say, but almost all of us sound the same to them.
If you do lose, check on those companies periodically. Chances are that they will be unhappy with the service and you can pick that up at a greater cost than normal. Then, when the machine comes up...you have a leg to stand on by being able to offer customer priced maintenance on something they have seen work.