Ian, I charge £150 / £160 for a 4 bed house, UNFURNISHED. If furnished add a bit more about £15 ish. I charge £75 for a 1 bed, and £ 95 for a 2 bed.
Your prices should be the same, your doing the same job, just different kit. It will take you longer, so your charge should be similar.
Regarding getting work from them, face to face is the best way, but as they will already have a carpet cleaner, you need to keep reminding them, nicely that your there.
ps is a mentor similar to an agent, do I get a percentage?