ALOT!!! for one kikyo and kagura die for good, and well there are websites that let you read it for free like onemanga.com and adinuyasha.com!!! They have all the translations
And he lives happily ever after married to Kagome.
you can probably buy it on the internet but if you can't find a way to buy it online you need to search for a shop with manga's and comics normally they'll be able to obtain the manga for you or they...
That is the way most anime is...just like in full metal alchemist and fruits basket...the manga version if much diffrent than the anime version...i think its because when the anime creator took over...
Sesshomaru helps inuyasha kill naruku in the "Final Act" and goes back off to the western lands to make a new empire or city or w/e it is for demons and leaves rin in a village but visits often.