You seem confused Frank. I didn't mention performance related add-ons. Transfers usually have a guaranteed minimum amount that's to be paid + possible bonus's depending on performance. That minimum amount does not have to be paid in 1 lump sum, it can and often is spread over several years..
I only mentioned performance related add-ons as they are usually a part of majority of player transfers (although only a small part of the final figure).
No it doesn't
have to be paid in one lump sum, but most selling clubs insist on the bulk of the "gaurenteed" amount being paid upfront.
There may well be payments continueing from this gauranteed amount for a number of years, what I highly doubt is the initial down payment % you initially stated as low as 30%. No way at all Neymar, Bale or Cavani etc etc would have had this low initial payment.
edit - according to CW 's figures RM have already paid 66% of Modric's fee (give or take a few %), and Im sure this is based on the initial lump sum paid, not any subsequent payments.
Unless something specific is wrote into their contract regarding a cut of any transfer fee received for them and also whether that's affected by a transfer request, then players aren't entitled to any bonus related to their transfer.
Exactly as I said before - the more senior/ experienced the player (in his side)the more likely a specific entry is going to be in that contract.
I don't believe I implied it was standard by any means. I certainly never meant to imply that every player is entitled to a bonus from the selling team. apologies if you thought that was the case.
Whether its true or not is another matter, but there have been items in the press of players being given a golden hello from the "buying" team for a star player running his contract down and leaving /arriving on a free
(although admittedly we are discussing "paid" transfers rather than free ones).