I didn't state that Chinchillas are "the only one on [the] list suited to outdoor life". In fact, I wrote: "However, I wouldn't recommend an outdoor husbandry for most of them, especially not in Pennsylvania." That would include Chinchillas under most conditions. For a good outdoor exhibit, degus or Mocós might-to a certain extent-be the better choice among the Caviomorpha.
And no, it's not a "matter of opinion": Siberian chipmunks are not only prone to chronic stress as previously mentioned, but require a very diverse and balanced diet, a lot of room and are prone to infectious diseases of the gastrointestinal tract, if fed inappropriately. Additionally, they can harbor quite a bunch of "nice" zoonotic diseases (like Listeria monocytogenes, Yersinia pseudotuberculosis, Francisella tularensis etc etc). The latter is also true for other species mentioned, but the tendency of Siberian chipmunks to bite and claw quite severely when feeling provoked increases the danger of transmission. All in all, I wouldn't label them as "perfect beginner animals"-a term which is too often misused, imo.
However, as Steve Robinson correctly pointed out: if LizardInsanity has such a limited budget for obtaining the animal alone, how to pay for a roomy, secure and well structured outdoor aviary needed for Siberian chipmunks, degus or whatever else? Maybe your Syrian hamster advice is the best one, next to Steve Robinson's hint to spend the money on the "house full of animals" instead.