How did the average Jews during the temple era afford all these sacrifices? Reading the Talmud it seems like with all the possible ways to mess up we would be buying up premium(unblemished) cattle and going up to Jerusalem every month or two. How did we all afford this and how were they able to do these frequent journeys across Israel to Jerusalem and back home without modern transportation? It seems unfathomable of a task. How did we do it?
It is possible that the most frequent sacrifices were not expensive animals but instead cheaper offerings of birds or flour.
As suggested by @pcoz in comments, I note that Sefer HaChinuch explicitly writes multiple times that the Torah prescribes "cheaper" sacrifices for sins that are commonplace (for individuals of lesser means). This applies to e.g., violating an oath, eating sacrificial meat or entering the Temple while impure
See mitzva 123 - the commandment of the variable sacrifice
- He was lenient upon them [regarding] the atonement of these sins that are mentioned - that they be according to the wealth of people or their poverty - as stumbling in them is [common] for people. As there is no doubt that (every) sin of the the tongue is more [common] and frequent than the sin of action
- also regarding the impurity of the Temple and its consecrated [foods], it is known that stumbling is common with it
- from the frequency of the matter and its lightness in the eyes of the masses of people, it was from His kindnesses, may He be blessed, that the atonement be whether for the inadvertent or for the volitional