We apply to cuprates a three-fluid ideal boson-fermion statistical model of
superconductivity in two dimensions (2D) derived from three extrema of the
system Helmholtz free energy (subject to constant total fermion-number) fo
r the BCS model interaction between fermions. The same interactions absent
in BCS theory are neglected here. As the ensuing bosonic Cooper pairs move
not in vacuum but in a Fermi sea we employ the correct linear-as opposed to
the commonly-assumed quadratic-dispersion relation in the center-of-mass m
omentum (CMM). More importantly, pair breakup beyond a certain (very small)
CMM is accounted for. Bose-Einstein condensation (BEC) critical temperatur
es of about 800 K result for moderate coupling with cuprate parameters.