While I agree that 10 watts of tube amp does not equal 100 watts of SS power, I'm not sure about the idea that tube amps won't work with Magnepan speakers though the small budget would be a problem unless something used can be found.
Here is another Audiogon thread on the topic:
https://forum.audiogon.com/discussions/tube-amp-for-magnepan?highlight=magnepan%2Btube%2Bamp
I had always heard that it wasn't necessarily the amount of the current, but the quality of the current that makes the Magnepans sing.