Henry David Thoreau has gathered the following information. Could you help Henry calculate his gross profit? $[$Your answer needs to be in $$123,456\mathrm{.}78$ format$]$

Gross sales $$25,000$

Sales discounts $$3000$

Beg. Inv. $$2000$

Net purchases $$4,000$

End. inv. $$2,800$

Operating exp. $$1,800$

Beg. inv. $$2,000$

$+$ Net purchases $$4,000$

$-$End. Inv. $$2,800$

COGS $$3,200$