I doubt you will get a cheaper solution that actual power supplies. Here is an example at $65 for 10. https://www.ebay.com/itm/165149435995 There are many listings like this. This is the first I found in ten seconds of searching.
Manufacturers like to put signaling between the power supply and the laptop to lock you in. Get the wrong power supply and it will not work at all or if it does it will throttle the CPU and/or nag you constantly. You need to find out if your ithems do that or not. If they do you need the proper power supplies.
By the time you find a power supply and source the connectors, it will likely exceed the price of just getting the actual units.