First I know most people here will just call shenanigans with what I am to ask for help with and that is fine I completely understand that reaction. A small amount of back ground info. I have for the past 15 years been playing d&d/pathfinder with the same 2 people we take turns as gm and our games due to limited gaming time can take years. I am the min/maxer of the group and when I am gm I like for my players to be...Heroic (at the same time my games are not easy even with this power i have almost killed them a half dozen times, i love swarms lol) and they would never be allowed to use there characters in other games but the people I play with are very good at not abusing my impulses even tho I like to through in home-brew (epic)magic item just to see what will happen lol.
Now the point. for the last year or so i have been working on a god of knowledge built library filled with all the collected knowledge of many world (i know op). Also let me point out this place is not easy to fine at all. I leave clues scattered around the world some of the big ones very hard to find but always in areas they will be so they at least have a chance. Each time the find a clue they get a bonus on research about this library. The finding of this place is akin to Test of the Starstone but you dont become a god your just really freaking op. Once a player is in the library they have access to incredible knowledge and as such with enough time can gain powers beyond what a normal character would ever achieve. There is a back story for this place but for this post its not really needed.
The rules for this place i have set so far.
While inside the characters do not age (time stops) or need food or sleep.
There are also 5 crystals that allow them to teleport to basically anywhere (i know op) when they go from location to location they must always return to the library first.(don't lose that)
Each time a player is about to lvl they have they have to option to sack that lvl for points spend in the library (the sack of the lvl is meant to show to use of time spent in the library learning the new stuff for there character) in order for them to lvl again they must reach the lvl after the one they sacked.
example: Say a player is about to go from 10 to 11 well they can sack that exp and go back to base exp for 10 and use the points gained to power up the character. for them to lvl again the must gain enough exp to go from 10 to 12. once at 12 they can gain the lvl or repeat the process this time having to reach 13 from base 10 exp.
Any ability, power, feat, stat increase, and spell(class or non-class) they want to gain must be usable by there current lvl. (so if they want the really good stuff they need to start gaining lvls at some point)
What i hope to have at some point is a system of rules that will work for any combination of classes and number of players.
Why am i stuck, well here is the questions i am having trouble with.
How many points do they get each time and at what lvl?
How many points will the new "stuff" cost? (+1 to atk/def will be pretty cheap but magical flight?)
Do i have a set number of "stuff" they can gain or just leave it open?
Any advice or guidance would be helpful.
For the people that have read through this wall of text vomit i thank you.