what printers are compatible with MAC Mini sequoia 15 o/s

Any AirPrint capable printer will work.

for the long list, see > About AirPrint - Apple Support

Remember the old saying "you get what you pay for" yea well' that saying also includes printers.

My vote goes for Eco-Tank printers, because they are way cheaper in the long run to operate.

see > https://top10best.how/ink-tank-printers?

Almost all of them. Most printers these days support wireless printing (AirPrint) and require no drivers. Stick with the name brands HP, Epson, Brother, Canon, etc.