Maybe its worth learning how to do some of the simpler things, like the oil change ant spark plug change - like you say, parts are cheap, and provided you have decent tools and work methodically and carefully, you'll get it completly right and save a packet
Where abouts do you live? If you live in / near london you could get your bike to spannerman (he's a member on here, Stewarts Motorcycles if you google) in the future, he does an excellent service and dosn't charge the earth