Dr John Stockton wrote:

For the present rate of drop of about 1 mm/s, the drag is equivalent to
about 0.05 micro-g; for M = 200 tons, that's 0.1 N implying 3 MN-s/yr.

So if the reboost is done with the Progress main engine with a nominal
Isp 305 s = Ve ~= 3,000 m/s that's 3e6/3000 ~= 1,000 kg/yr of
propellant, no? That seems low from what I remember of the Progress
fuel capacity, but I may be misremembering.