This is hugely complex decision. I'd ask that the district investigate options and perhaps the PTO contribute funds towards a solution. There are so many factors to consider, this could be very difficult for a PTO to make a good choice.
Many copiers now are multi-function machines that can be integrated into the computer network, used to scan images, print from various desktops, AND make copies. Even just on the copying side, there are lots of options in terms of sorting, stapling, duplexing, folding, speed, capacity, etc.
Yes, copiers can easily cost as much as house! Low end/low volume models probably start at $2000 and can go up to more than $100,000.
When an organization plans for new a copier, you have to estimate the potential volume (which no matter what you think you know - it will be more). Youll need to know if it's better to lease or buy, what features are required, if it needs to follow other standards - such as using the same toner cartridges as existing equipment or be a certain brand or model that can be supported as an extension of an exisiting service contract. And definitely you need to figure out how service/repairs will be handled.
An organization can totally own the copier, buy supplies as as needed and repair services as needed. It could be in a situation where everything is included and you get billed a per image cost. Or any hybrid in between - often where you have a plan that allows for X number of copies per month and certain services/repairs.
The on-going cost of toner and paper can be extreme, so knowing who will handle that is important as well.
There is so much to investigate on this, I'd be hesitant to take on the procurement piece as a PTO.
That being said, if your group has the funds and feel a new copier would benefit the kids (more/better handouts, teachers spending more time in the classroom and less waiting for copies, better communication, etc.), then helping pay for it could be justified as a PTO expense.