It's actually very good money, because players are entitled for bonus, endorsement share & tour fees.
However, the financial model in BD cricket is aligned with the Australian model, which relatively benefits the lower tier more. BCB pays very good money for central contract at FC level, I think around 100 top cricketers are under central contract for their FC teams. Players are paid good match fee for domestic matches. On top of that, Dhaka League is out of BCB's direct control, which has 16 (or 20) teams in 2 Divisions, where over 250 players are listed - this is actually a professional league & players are well paid, for 10 weeks work; I believe top players earn over $50K from their clubs. Now, BPL has 7 teams, which also pays good money to top 100 cricketers. On top of that, players at FC level are insured by their teams/regional boards on medical & I think, they are planning for a pension scheme, but not sure. It's actually is quite good money - might be top 25 players don't earn much compared to others, but in BD over 200 players are paid decently enough to focus on cricket for 2 decades.
Regarding corruption, I think more than money or patriotism, it's the system that protects the players most. Even the least patriotic player also knows that an illegal payment f $20-25K can cost their career worth of $20-25 millions. Most of the PAK players are entrapped in their early age, because of the poor system (which forces young players to find a godfather) - by the time they reach to national level, bad company almost black mails them to submission. More or less, BCB has established a funnel, which filters players from teen age - players like Miraj, Shafiul, Afif, Saif, Mosaddek, Taskin ....by the age of 16 actually do have a career path from BCB - Junior teams, academies, BKSP, or Dhaka League Clubs; therefore unless someone is really dumb, won't allow shady people to entrap them, won't require either. At lower level, club matches, privately owned leagues, there are lots, lots of fixing - some for money, some for points, some for other favors - which doesn't touch the players that makes the highest level ...... still there was Ashraful, hence, you never know