I'm looking for a software solution to maintenance of equipment. I am currently using One Squared's The Asset Manager for my depreciation, and I can use that for some of what I want, but I'd rather have a separate application with all the maintenance related stuff in it, and be able to let people that have no need to know about financial stuff use it.
 
I'm not looking for anything fancy or involved, primarily a maintenance schedule/calendar and a Common Parts & Supplies list.
 
Oh, while there is no "budget limit", I don't want to spend too many hundreds.....
 
Any suggestions?

Not sure exactly how you want to structure it but couldn't you set up a separate company in DBA to manage it?  Might have to get a bit creative but I bet you could do it.

PME Preventive Maintenance & Equipment Software
http://www.cool-ware.com
 
We have used this software for several years, but looks like the price has gone up to $479 for single user.
 
You might want to check out DBA NG just for tracking PME since it's free to you.   From the help file:
 
The Service & Maintenance module is used to manage the service and maintenance of Assets such as machines, tools, facilities, vehicles, etc.  Assets can be internal Assets or Assets you maintain and service on behalf of customers.

Not sure if this is what you are looking for but it is a company we represent.  Our target market is small water and wastewater treatment plants but have found it works for pretty much any company.
 
http://www.opssys.com/mm.html
 
Mike