In BB it's just impossible to keep a 250k player for several seasons in the D3 or lower, so farm teams here are less effective than in HT.
NT players in HT are fed by a cash vault -- no-one expects to make enough money on a weekly basis to pay their salaries.
This is quite possible in BB as well -- 7.5 million will feed a 250k player for 3 seasons, and a lot of teams can raise this type of cash by selling out their current rosters.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."