How to decide which technology hype is worth personal investments?

I think it's very important question. Because studding some new technology requires some time (and maybe money).

So, I've created for myself brief checklist which helps me to make this non-easy decision.

1. How long it will take for me to master the major approaches of selected technology?
2. Can I reuse the gained knowledge during my daily development work?
3. How long it will take to train/coach my team mates to use this technology?
4. How big is the market for the selected technology?
5. How big is the local community for the selected technology?
6. How easily can we hire new developers with appropriate knowledge in selected technology?
7. Will it be profitable to have the knowledge in that technology?

I know  that some items are very boring  and mercantile, but it's life, real life. And we should align our priorities appropriately.