mrmatto
Autocross Champion
1. Take old tire off good rim, but new tire on good rim.1. Normally, the $35 charge is to put new tires on wheels (or rimz) and balance
2. You are asking them to take a tire off of a wheel before you do #1
and yes, normally you'd do #1 before #2, but in this case you need to do #2 before #1
Accordingly, there is additional labor involved - if I understood what you asked.
2. Take good tire off old rim, put good tire on new rim.
It’s the same process and order of events, seemingly.