(a) According to Rebbi Eliezer, a Zar who is Chayav to pay the Kohen Chulin that is fit to become Terumah is permitted to pay with a different species (e.g. dates for having eaten Gerogros) - provided he pays good quality fruit (even if what he ate was inferior.
(b) Assuming the payment is 'L'fi Damim (according to the value), rather than 'L'fi Midah' (according to the measure, irrespective of the value) - this will mean that he is obligated to pay fruit that the Kohen will be able to sell easily (even though the value is the same anyway).
(c) Rebbi Akiva holds - that he has to pay the same species that he ate.
(d) Assuming the Zar ate, say, cucumbers of Terumah in Erev Shevi'is (which is one of the first species whose last year's stock is finished) - (where he can neither pay with another species [from last year's stock] nor can he pay with cucumbers from the Shemitah year [see Bartenura]), he will have to wait until the following year and with freshly-grown cucumbers.
Rebbi Eliezer Darshens the Pasuk "ve'Nasan la'Kohen es ha'Kodesh" to mean - that the Zar must pay with anything that is fir to be Terumah; whereas according to Rebbi Akiva, it means - that he must pay whatever species of Kodesh that he ate.