It would help to know where you will be located.
For instance, we have planted about 50 fruit trees in the 8 years we´ve been here -
most of which have survived and we are reaping the fruit.
We bought all ours, a few at a time, at the general market held every Friday in Tomar.
There are several vans selling fruit trees. There is bound to be a similar market near
where you move.
Or Agriloja shops sell them (a bit more expensive, but still cheap compared to UK prices) and
again there is bound to be one near you. Other people buy from garden centres/nurseries.
If you give a location somebody from that area may have a better idea for you.