Ouch, sorry did not mean to offend. I was thinking if a carpenter came to fit a number of doors in my house, £10 each sounds reasonable. Yes, if it was just 1 door, then I would expect to pay more.
There is sometimes a delapidations clause in your rental contract that states that any damage outside of normal wear and tear would be your responsibility.
The new 2012 Onkyo models are now out, so it might be worth buying the latest models as they will be more 'futureproof' than an older model like the 309. i think network streaming is now a must, especially if you love music/ radio, so now you can get that in the entry level Onkyo TX-NR414.