As for highways...ODOT maintains the entire statewide highway system using only gas taxes and other motor vehicle fees. Yes, it's a tax, but it's a tax on those who use the system rather than property taxes which the state doesn't receive; Oregon doesn't have a sales tax and the income tax doesn't go to transportation.
What high cost item can I
not purchase, to avoid paying more than I want into the system?
The urban freeways are extremely expensive, and relative to the costs, the users pay less (based on the amount of gas they burn while on those roads) than most rail systems generate in farebox recovery.
Unless those expensive roadways were
TOLL Roads.
Rural highway users aren't paying enough for the paved roads they have, since there just aren't enough drivers driving on them. Yes, their roads are comparatively inexpensive in relation to urban freeways, but the ratio is still the same. Maybe close to 30%.
A tax, any tax, used to pay for something that thosed taxed do not either use, or use very infrequently, is a subsidy. The Latin root of the word is:
" from sub "behind, near" (see sub-) + sedere "to sit" (see sedentary).
It was in reference to the taxes needed to support a standing army, even in times when there were no conflicts.
It's not a matter of roads, passenger rail, air travel, or sea travel needing subsidies to survive, it's a matter of having a clear understanding of what the costs and what the perceived benefits are, and whether they're worth it.
If we went to a pure market driven system, you might just see a streetcar/passenger rail renaissance, and the demise of 'freeways'.