It's really hard to answer as there are so many unique sales and situations out there (and coming in the future no doubt). It really depends on the title, rarity, amount and quality of restoration (not all restored/backed posters are created equal that is for damn sure!) and timing...
That sure is the truth - not all restorers and backers, let alone the work they do, is/are created equal.
And because of that, (and this has been asked before, yet
never answered), why dont those dealers and auction houses that know who did the restoration work, let alone those that send items off to be restored and backed,
EVER name the person who did the work? Why is that identity kept hidden and secret? That is just as important as the work they perform, imo.
And if someone bids on and wins a poster that has been poorly restored, (but that poor work cant be seen in the pics offered), that person should have the right to know who did a less than stellar job. Same goes for all those posters that look fantastic, post-restoration. That
artiste should be known and able to be commended (on forums like APF) without his or her name forever being kept in the shadows.