So, I have a game starting next week Saturday, and I am split between a Bladebound, or a Rogue that I'm going to modify it's weapons and invest most of it's gold to get a rapier that is an intel. sword. Since we are starting at level 8, we'll be given basic starting gold for level 8's which is 33K if I remember right.
The rogue/shapeshifter(Ranger) will use about 25k on the sword, creating a level three weapon that will have dark vision making up for the fact that my character won't have dark vision the sword telling him what's there, also speaking telepathically he'll be able to tell me without giving away my position. Also, he'll have a sneak attack (if rogue).
(Sword Stats)
Katana +3
Damage (1d8) +3
18-20/x2 Crit
Deadly: +4 when calculating Coup De Grace
Telepathy
Senses 120 feet
Darkvision
Ability scores 18
Level 1 spell/3x a day
Ego 9
26240
Or the bladebound which will not have to spend money on his weapon, so he'll focus more on armor, and other things to help himself. Allowing him to be better at survival.
Sword Stats
Katana +2
Damage (1d8) +3
18-20/x2 Crit
Deadly +4 when calculating Coup De Grace
Telepathy
Unbreakable
Senses like a creature 120 feet?
black blade arcane pool
Gives bladebound Alertness
Ego 10
I can't figure out which one might have better benefits. I like not worrying about preparing spells, though if the benefits are too good to pass up I'll go into it, but I do want an intel. weapon for the roleplaying benefit.
An intelligent weapon is more like a plot coupon. It's something that the DM would hand out during the course of play, not something that can just be purchased with gold.
If your DM's given you the chance to buy one though, that's perfectly acceptable. But I'd ask him if you haven't, since an intelligent weapon with a suitable spell 3/day is pretty much one of the more powerful things a character could have.