So rules-wise you're basically talking something along the lines of "
The d20 SRD starting at ECL 15 (105,000 exp); base stats must average 10, but full retroactive modifiers apply (thus, in addition to the average of 10 for base, you have an additional 5 points to distribute from "leveling up" through your initial 15 levels ... if you don't use a template that deplets your class level any). You can roll any numers you like, but if your average for a particular die-type diverges too much from the expected average for that die type, the Game Master will apply a penalty. Magic items may be pre-purchased at an EXP cost equal to twice that of the EXP cost to create the item in-game if you do not meet the item's pre-requisites, or equal to the EXP cost to create the item in-game if you do meet the item's pre-requisites," correct?