Acquisition cost is high but lifetime operational costs are quite low for Gripens mainly thanks to the immortal GE F404/414 engines.
With all due respect to our Chinese friends, Chinese military hardware especially aviation equipment are inherently unreliable. Bangladesh Armed Forces are not happy with their Chinese inventory and are diversifying away wherever possible.
We have lost many servicemen to Chinese equipment malfunction (mortars and tank shells exploding inside barrel, F-7BG bombing itself (this one took the cake)), F-7MBs and PT-6s falling off the sky at random despite limited, measured usage, etc..
Chinese military aviation industry is still largely dependent on stealing IP from overseas as evident by the stark visible similarities of various components (F-7 vs Mig-21, J-10 vs Lavi, J-11 vs Su-27, J-35 vs F-35, etc..).
The fact that J-10s have seen zero export orders to this day despite many poor and middle income countries being in dire need for fourth gen fighter jets is very telling.