How to handle trades with keepers!?

League info: .5 ppr 10 team keeper league

  1. 1 keeper
  2. 2 years for maximum years to keep 1 player
  3. Only drafted players are eligible to be a keeper
    Rounds 1, 2, and 3 players can not be kept
  4. Each year keeper drops 1 round where keeper was drafted (ex. Yr 1= 8th round, yr 2= 7th, yr 3= 6th and than player can not be kept anymore.

How do i handle trades in this setting type?? I dont want people trying to trade a keeper (solid round value) for a top 5 player? I want trades to be fair for the player alone not count keeper value I wanna run mine like this:

“If a keeper is traded, the round that would normally cost the original owner that next year gets cut in half for the new owner. Ex: Owner A trades 7th round keeper to owner B that next year the keeper would normally cost a 6th but now will cost a 3rd (÷ by 2). If round falls on an odd # than that defaults to the earlier round. Ex: Owner A trades 6th round keeper to owner B that next year it would normally be a 5th but now is a 2nd”

Thoughts? Thanks footclan!!