Well, as an engineer who has been doing product management for the last eight years or so, I've certainly heard this one.
Certainly, customers will be concerned about maturity. I assume with the $10K+ price tag that this is a business-to-business application.
Your customers will have to go through a lot of hoops, checklists, evaluations and whatnot to purchase the product. One item on the checklist will for sure be "maturity" - having a version number greater than 1.0 might let it slide past that item - other likely items one the checklists will likely be things like "years in market", etc.
- IMHO, faking a version number isn't worth the likely benefit in circumstances like that - the product manager will have to defend that in every customer meeting.
Also, another quick rant - it seems like most slashdotters are assuming that the product becomes more "mature" the longer it exists and as versions progress - I'd say that for applications in this class this is not so. When you have a $10K+ app, the pressure will be very high from customers to feature fill at a quick rate - and if you want to keep the high dollar maintenance contracts coming in features will abound - quality is not likely to improve in this environment.