Well, the turns ratio on your transformer is 1:18 and you want some 700VDC if I remember correctly. This is 350VDC bevore the voltage doubler, and with no load, VDC will reach the peak VAC value, so 250VAC rms would be enough for that. Under load however, it is likely to drop a fair bit, so I would rather calculate 300VAC rms.
This in turn requires 300/18 = 16.7Vrms on the primary side, which is ~23.6Vp. Since your supply is only 9V, this would require some step-up process, i.e. even though you cannot apply more than 9V in the active phase, the coil voltage will get significantly higher in the opposite polarity when the transistor is off. I would aim for a more symmetrical primary voltage swing instead, as you probably have severe distortion, i.e. strong 2nd harmonics right now, which cause a DC component in your primary current, that compromises magnetic core properties and efficiency.
I would try to find the optimum working conditions for highest efficiency now. Measure the current consumption for different supply voltages (for the primary coil and MOSFET only, not the driver), e.g. from 1V to 9V in steps of 1V, and also measure the output voltages. As you presumably have a resistive load, you should be able to calculate input power (V_supply * I_supply), output power (V_out² / R_load) and see what efficiencies (P_out/P_in) you get.
The snubber network needs to be optimized for the individual design, so it would be better to leave it out for now. I wondered why the currents are so high all of a sudden, compared to what we've seen before. I suspect it is because of this network, which might not be well suited for your circuit after all.
Once you've found the best operating conditions in terms of efficiency, you get an idea what to change in order to make the circuit work for your particular requirements, i.e. 9V supply voltage and 300VAC output...
Good luck with your further experiments!