  In this work we analyse 3 average-luminosity hard X-ray selected AGN: ESO
506-G27, IGR J19039+3344 and NGC 7465. They have simultaneous Swift/XRT and
NuSTAR data never published before and have been poorly studied at X-ray
energies. These sources make for interesting targets both from a methodological
and scientific point of view. Scientifically, they are of interest since they
are possibly heavily absorbed objects, belong to a peculiar class and are
variable both in flux and in spectral shape. Methodologically, because it is an
interesting exercise to understand how existing spectral models can be applied
to faint sources and how the use of NuSTAR data alone and then simultaneous
and/or average data impacts on the spectral parameters determination. In this
work we demonstrate that simultaneous data are not sufficient if their
statistical quality is poor. Moreover, we show that also the use of
time-averaged data when dealing with faint AGN does not always provide
confident results as for brighter AGN. Regardless of the poor data quality
employed in our analysis, we are able to provide insights into the spectral
characteristics of each source. We analyse in detail for the first time the
iron line complex of ESO 506-G27, finding not only the presence of the iron
K$\alpha$ and K$\beta$ lines, but also of the iron K edge around 7 keV in the
NuSTAR data. We also highlight changes in the absorption properties of IGR
J19039+3344 and confirm NGC 7465 to be an unabsorbed type 1 LINER.
