I'm asking for your honest opinion: If "we" are, (for the lack of a better term) "forced" to trade Nylander, what or who should we expect in return?
That's impossible to answer without truly knowing what his contract expectation is.
There is definitely a number where it would really start impact the expected return by shrinking the market of interested teams.
If the Maple Leafs decide to trade him they want as many interested parties as possible to drive up the price and have a larger pool of offers to choose from.
But Nylander's contractual demands will definitely affect the amount of teams interested in him. If he is expecting a $7 million deal I'm sure there would be ten or so teams interested in him at that price. At $7.5, that number starts to shrink a fair bit and at $8 million, you might be down to one or two teams that would be interested and they would not be paying a premium to acquire him.
I think the best case scenario, in terms of making the Leafs the best team they can be, would be to trade Nylander for a defensemen that could develop into a key part of this core going forward, but that only works if Nylander's contract demands are reasonable so they can acquire as good a blue liner as possible.
If he's looking at a contract in the sevens or eights, that's not going to happen.