If I may take it one step further, although I realize I am bound to receive a lot of criticism and possibly upfront denial.
I would suggest removing all of the different editions, and solely providing one true community edition for free. Yes, free. While the TimeTrex team may find the product reasonably affordable, which is subjective to everyone, I really believe your market penetration and adoption can expand exponentially based on the following suggestive points.
1. Focus TimeTrex's efforts on creating the World's Best Open Source Payroll & Time Management Software and keeping it that way. Beware of forks and clones due to strict limitations.
2. Provide all of the current Business & Pro functionality in the one Community Edition. Allowing customers to use all of the features without having to spend a cent is essential when selling software. If they like it, and they grow, perhaps they will purchase support or customization from you.
3. Allow integration of standardized hardware. This is such basic and fundamental functionality if you are using TimeTrex to pay hourly employees. (Again refers back to my original point of most small businesses being really micro-small businesses with few employees and limited resources to really perhaps pay salaried employees).
Again I understand you are in the business of providing software and adding value by up-selling the additional features and hardware, but I really think you may be limiting yourselves by holding back these features and splitting them into all sorts of editions. Offering all off the business functionality and opening it to standardized hardware (that the community can expand support on if they wish), in my opinion would significantly increase your adoption rate.
To be frank, holding back features you can easily provide seems like a dated way of selling software. Focus on what you're good at and make sure the community appreciates it; don't potentially stir the pot by allowing competition to arise and copy your software and undercut you. TimeTrex should be the one undercutting and providing a well rounded software being the small dog in the fight compared to other paid solutions, take advantage of that, after all can someone really undercut free?
While I may not have the facts and numbers of your customer base, I would venture to potentially say most small businesses can't afford the support, customization, implementation and other services you offer when they start-up. Once they get going and business grows, I am sure then they can spend some money on these services. Why not allow them to have the product for free, let it grow in their organization and allow them to let them grow with you?
It is my opinion that focusing your efforts on selling implementation, hosting, service support, etc services, even selling non-proprietary/standardized hardware to those customers that want it is key. The customers that outgrow the ability to manage their own TimeTrex installs and support, will more than likely come to you because you designed it and support it, these are the customers you want.