Welcome to the normally playable leagues!
Home playoff games are huge, I assume you get all the gate receipts, which means money naturally.
The standard strategy to player recruiting at these low levels is trials, trials, and more trials. Typically most teams can only afford free agents that are interested because the money situation is not great (to the point that FA Cup games are absolutely vital), so the trial is more for attribute/personality scouting.
@erik45 is applying a harder version because most of those free agents aren't eligible choices due to the restrictions added, and the eligible player options have really high wage demands even for a relatively rich club like FC Isle of Man, so he's effectively youth-only.