Roma had their first offer turned down, but are now stepping up talks with Santos for striker Marcos Leonardo, reaching €18m with various bonuses.
However, Sky Sport Italia insist that was just a starting bid and paved the way for immediate talks to step up the cost of the operation.
The basic fee itself will only go up to €10m, but the big difference is that the various add-ons and performance-related bonuses will reach up to another €8m.
That includes a percentage of the sell-on fee that will be given to Santos.
They are still discussing the terms of the deal, such as the timing of the payment over instalments, and it could even be a loan with obligation to buy.
Santos had wanted at least €15m to part with the Under-20 World Cup star, previously rejecting a €12m proposal from Lazio.