Is moving up this way okay?

Depends on what it's worth to you to get to the higher levels faster. You're going to pay a poker tuition, it happens at every level, either by negative BB/100 or reduced BB/100 from what you're used to.

If you blow the 25k on higher limit, but learn enough to make it a profitable game for you 2-3 years earlier than you would have reached it otherwise, was it worth it?

That's only something you can answer. For me, if I knew I'd beat the higher level games after a time, then I might go for it. The fact is I don't know if I could beat them and it'd be devestating emotionally to blow all that money with nothing to show for it.