Buy stam or buy xp

If you have fsps and want to use it to power level. Should you buy stamina or buy experience?

The 2 upgrades that I am comparing are :

+25 Current Stamina (cost 1 fsp)
+1% Experience towards next level (cost 2 fsp)

Some players frown upon the second option, but I think it is fair game. There are reasons why you will not buy experience, such as buying experience will not add to your guild experience. It will also not get you any creature drops, if there are any that you wanted. Setting those aside, is it better to buy stamina to kill creatures or to buy experience?

So at level 431, I took 10 samples of average creature xp. I got it as 32567 (halving when librarian activates). Assuming you hunt like me with 16x doubler, level 175 Adept Learner and Level 225 Librarian, the librarian should activate 22.5% of the time, giving an average of 39637 xp per creature attacked. Assuming 2% misses and 50/6 stam used for shield imps when you miss, the average stam per attack comes to 16.4867. That means, for each fsp, you can buy 25 stam and gain 60105 xp. 2 fsps can buy 1% xp, and at level 431, that is 55599 xp. So it is definitely better to buy stamina than to buy 1% xp, at least at level 431.

Even with CA 100, 2 fsps of stamina an still buy 96362 xp, significantly more than buying xp. Even if creature xp does not increase (and it does), that is more than 1% for level 567. Added with the the advantage of getting gold and possibly item drops, and xp contribution to guild, one should clearly buy stamina instead of xp. There are some instances where it may make sense to buy xp. One such possibility would be where that 1 % gain means you don't need a higher buffs to kill a tough level, or perhaps that 1 % puts you over a level so that you don't have to walk to a far realm. But those upgrades should be used sparingly, and buying stamina is almost always a better option.