I'm at 1100 mile so I'm due my first service.

Harley want 230 pounds which seems a bit steep

Given its under warranty still is it worth having Harley service it or would my local indie be just as good?

I believe it can affect resell value (not that I could ever imagine selling my bike!) .. also could it affect my warranty?

 

I was in the same boat, bought a service manual and did it all myself, think it cost me $100 for 4 qrts of mobil 1 with filter and 1 quart of redline shockproof, grab a torque wrench and check all the bolts listed, mine were all fine, only problem i found was the front cylinder spark lead was rubbing against the fuel line. dont know about warranty probaly screwed mine but hey its a new bike, did all the work on my 65 triumph and 49 panther so for the money hd charged I'm hoping nothing goes drastically wrong.

 

Probably should check with UK laws. In the USA, indies (or yourself) can do the work without voiding warranty. Just keep receipts. But different countries have different regulations.