I am looking for an affordable flourocarbon line to use on a 2500 size spinning reel, for finesse applications. I am looking for something that is manageable, will last, and will not break the bank (aka Tatsu) My budget is around 25$. Thanks!

Yo-Zuri Hybrid UltraSoft isn't a true fluorocarbon, but it has many of the same positive characteristics. In addition, it's very manageable and less expensive. 

I've not found a true FC that handles well enough on a spinning reel except for very light tests, like 4-6.

I used to fish straight fluoro for finesse applications and you'll find yourself changing your line about every 4-5 outings. I finally got on board with braid and a fluoro leader that's the way to go.

One more for braid with a leader, try it you'll be glad you did. 

Braid and leader x3

 

I get by fine with Seaguar Red Label in 6lb and 8lb on spinning tackle.  Invisx is a little more manageable but also more expensive.  

You'll eventually end up with twist/management issues with straight flouro on spinning tackle no matter what line you use...How fast it creeps up depends on what baits/techniques you use.  Keep an eye on diameter too, not all brands/lines are the same diameter...For example, 8lb Trilene Flouro is thicker than Seaguar 8lb Flouro  Thinner = More manageable.  

i use gander mountain 8another sitelouro 400yds for cheap one spool last me about 2-3 years but i dont use that rod every time i go out either i also dont fill the spool knowing eventually im gonna pull it all off and restring it.  i think a 400yd spool is like $14-$16  so its like buying one and getting one free makes it more cost effective.  and its not bad line either or atleast i havnt had any issues yet

Braid and leader. I do have one spin rig loaded with 8lb P-Line Floroclear. Throws great. Never liked straight floro and spinning.

Funny.  I've never seen a fluorocarbon line with the brand name braid. Where are you guys finding this stuff?

I use 10lb Invisx on my Diawa Advantage 2500A spinning reels and don't have any handling issues. I wouldn't use 10lb on my Shimano Sahara 2500 because of the smaller spool diameter. If your 2500 size reel is a Shimano then 6 lb Invisx shouldn't give you any problems.