Educational one is Complete and full version with no restrictions but.... you cannot sell any work you do with it otherwise you can be prosecuted. When I was going to school I bought an educational version for 395$ usd. As a super bonus when you own an educational version you can upgrade to a full licenced version for the price of a regular upgrade. So 395$ for educational version + 395$ or 495$ for an upgrade and bam you get a full licenced version.
Ooh check this out just did a little searching.
http://www.sharbor.com/products/NTKN0300050.html
http://www.sharbor.com/products/NTKI0300030.html
Thats a full licenced version of Lightwave for 768$ Nearly 50% off
Also you can just buy the student version and use it till your ready to buy the full version then toss in 399 bones and your set.