Susan Roemer wrote:
My very old adobe product software will not work on new mac mini so would need to get just photoshop.
Adobe does not sell Photoshop these days – they rent it, via "subscription". The cheapest way to subscribe would be via one of their Photography Plans. If you don't plan to do a lot of stuff with the Adobe cloud, there is one that gives you access to Lightroom, Lightroom Classic, Photoshop, and 20 GB of Adobe cloud storage for $9.99/month. A Photoshop subscription that gave you access to Photoshop and Adobe Fresco would be $22.99 – $34.49/month.
One non-subscription alternative to Photoshop might be Affinity Photo V2. There's also Photoshop Elements. Both go on sale often.
Serif currently is running a sale where you can get an "Affinity V2 Universal License" (all applications, all platforms) for $82.99 USD. Photoshop Elements lists for $99.99 USD, but recently was on sale for $69.99 USD. I'm sure that if I wait a few days or weeks, I'll get more e-mail telling me that it's on sale for $69.99 again.
https://affinity.serif.com/en-us/