I've never purchased a complete set before but I do keep track of prices.
Most of the prices realized on complete sets still have break value IMO.
The rare or super high grade is the exception. If you sell your complete set
of e90-1, there is a chance that the bidders will be dealers that will stop bidding
when the possibility of profit disappears. 119 cards will take some
time to sell and sometimes a chunk of money is more useful; it really depends
on what you need.
One feature that I think needs to be added to VCP is set break price average.
You can already set the page to show the average VG-EX price per card,
now they just need to add it up for you
It wouldn't be exact but at least
you would have a ballpark.