In general any movement posted for a valuated material has a financial impact, except transfer postings that just change the stock status (quality- unrestricted - blocked) or move material from one storage location to another.
if you did something wrong wiht financial impact, why do you then think to correct it without financial impact? it does not make much sense to me, to correct only a part.of something wrong.
if you want to correct something in SAP then you have to do this in the opposite direction as entered.
This includes that you must not correct the wrong price before you cancelled the movements, otherwise you make the situation even more worse.
so if you have it like this
1 GR receipt
2 goods issue
3 change price
4 goods issue
then you sequence to cancel it is 4-3-2-1, nothing else.
as already said, the 201 movement has financial impact as well, but the advantage is, that it has no reference like 261.
And you may even have value at the cost center left after you fixed the sitution becaues the 202 is done with higher value than the 201 to issue this quantity again. you may ask your FICO colleagues if they want clear this value with the difference in another account.
But it is obvious that a difference will remain if you care only about half of your problem.