no it is a 50% chance to get either 20 or 100xp
tested it on an alt, on all races.
you cannot buy ANY kind of tomes at level 5, and ONLY level 5.
u can buy the mini ones before it, and the higher ones at lv 8 as usual, and requiring to die in between... but at lv 5, no kind of tome works, under any circumstances
thank you.