Compatible AC Adapter for the Canon EOS C300 Mark iii

Open Box 12V, 10A Power Supply with 4-Pin XLR Connection (8')
Their price at the current date is 62.99$ USD. If you're in Canada expect to pay just over 100$ or so. You may want to buy an adapter with more than 12V (volts) but I kept it low to avoid giving the electronics too much juice.
The manual explains that 11.5V to 20V but not under or over.
10A (amps) and 120W (watts) are the other two parameters.
I've learned that professional power adapters are often much more expensive but seldom is there an explanation as to why.
I can't afford to mess up my equipment, but I did my best anyway to find the least expensive option.
indiprotools.c...