English to Chinese Bus/Financial Business/Commerce (general)

Because the building trade is dominated by a tiny number of big firms, which rake in vast profits by snapping up developable land and then [drip-feeding]a supply of uninspiring, boxy estates that lack any supporting amenities, thereby ramping up pressure on local schools and hospitals. The big firms have accrued this power because in our skewed land market, “planning gain” goes entirely to landowners and developers: so every time local authorities grant an area residential permission, land values rocket and the big firms are the only ones with sufficient resources to take advantage.

一点一点地供应？用哪个词比较贴切？