Like Every basic-starter set since 1996, its pretty much pre-gens + a module + counters/minis + dice + how to play. I can't say I'm imagine.
Assuming you want the game to make 4e-legal PCs (IE, a character that could theoretically be used in Living Realms), it would be wordy, but do-able.
Races: Human, Dwarf, Halfling, Eladrin, Dragonborn (2 pages each, 10 pages)
Classes: Fighter, Cleric, Wizard, Rogue, Warlock. To keep things less wordy, make only one possible build, and simplify Either/Or choices (defender-fighter, devoted cleric, brutal rogue, controller/staff wizard, fey/deceptive warlock) (probably 3 pages each, 15 pages)
Powers: 2-3 choices for levels 1-3 only; (probably another 6 pages)
Feats: 10-15 basic choices (3 pages)
Skills: Brief-rundown of skill uses (very brief) 5 pages.
Equipment: the default armors (no MWK) + most common weapons. Adventuring Gear List, + a few magic items. (10 pages?)
50 or so pages? It could be done, but it would probably raise the price to 30 bucks though...
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