Sign up at least one real customer for a free unpaid beta. Be open with them that one thing you would like their assistance with is determining proper pricing for your product/service.
Many times it is not difficult for them to get a rough price, or in the case of LEO's they are a tight knit community and police chiefs talk to each other (plus they have an annual trade show that I have exhibited at). They should be able to get you rough budgetary pricing directly or via knowing a colleague that is a customer of your competitor.
The other alternative is to set a realistic but slightly high price for your product and make the purchase a "discussion", which is what it sounds like your competitor does. Set the price at $5K/mo (as an example). If you get moderate push back, your price is about right. If you get outrage, your price is too high. If you can't collect billing info fast enough to keep up with demand, your price is too low. In other words, figure it out as you go. If you have a bona-fide business plan, then your price is based on YOUR valuations and assumptions, not your competitors price.