I don't know how much a taxi would cost you...probably around $40 or so...not sure.
Mears was $12 roundtrip per person, from ASMo to Sea World, a couple years ago. I would think Universal would be about the same, maybe a few dollars more.
The towncar companies are around $45 for roundtrip from Disney resorts to Universal.
People have posted about taking public buses, from the TTC, for a couple dollars, but I don't know how easy that is. You may have to change buses, but I don't know.
I'm sorry I couldn't help you more.
We are planning on going to Universal from a Disney resort, next year, and I plan on using a towncar service.