If your "label" says 250mg/5ml means it is 250mg per 1 ML shot and you only have 5 x 1ml shots at 250 mg.
So, if you were doing 500mg a week, that would be 2 weeks and one shot (5 shots at 250mgs). Get it?
IF your 10ml bottles look less than the 5ml, you need a new source bro, he is ripping you off!
The only Sust I have delt with is in 1ml amps at 250 mg each. Sound like you got some UG stuff my man