A good estimation would be an Hohmann transfer from LEO to MEO. It might be slightly more efficient if the burn would be performed in the upper atmosphere, due to the Oberth effect.
When you calculate the total required $\Delta$v for the two burns of the Hohmann transfer, you get about 2.3 km/s, so the total $\Delta$v to get from Earth to MEO would be about 11.8 km/s.
And to answer your followup question, you can use the same equations of the Hohmann transfer, but do one burn which brings your periapsis into the Earth's atmosphere. This will be slightly bigger than the circularisation burn of the Hohmann transfer at about 1.1 km/s, however the reentry would not be that much higher as for LEO. Namely 9.2-9.3 km/s for MEO, compared LKO of 8 km/s (note that the increased velocity is roughly equal to that of the initial burn of the Hohmann transfer).