AI Tool Testing
The market is currently flooded with AI tools so you could use all $250 on one month of various AI tools and try them out for next month. Then cancel whatever you don’t like and keep what you do; using the new years L&D budget on it each month.
Self Hosting (Hobby)
You could buy a Raspberry Pi and try self hosting some services.
Conferences
Find conferences next year that have tickets on sale now and buy in advance. For example my city has a monthly one for which you can by an annual subscription via one time payment