Last year, I would have immediately responded with a new scope. My Tek 2465 lost its smoke, and my 465 is hard to read under the time base knob. And with only two channels, I sometimes had to use the external trigger. Yeah, I know, first world problems.
So my response to free stuff would have been, "What the hell, let's get a $1400 SDS2104X+ and upgrade it!"
Now I have an SDS1104X-E, and it is perfectly suitable for everything in my immediate future.
I have some of those super-cheap USB logic analyzers and Sigrok/Pulseview, and they should do what I want for now.
I guess it would be nice to have one or two more computers with decent memory to explore Xen, Vmware, or other hypervisors.
But I think I am pretty much good with what I have, in the development and test department.
To answer the question, I would probably spend the 30 minute free money on some concrete in front of my garage. Sorry about that.
Oh, wait! Can I spend the $5000 on 50 months of Starlink?