I've tried a forum search, but to no avail!
Can someone tell me of a tailor in East London who's decent and not too expensive.
Neither in the East End, but some suggestions:
For tailoring (including adjustments): http://www.childandsons.co.uk/
For inexpensive made to measure: http://www.cadandthedandy.co.uk/
They are very reasonably priced...for Royalty!
Not sure, what is a reasonable price for a tailored suit in London? Up in sheffield you can get decent tailored suits from around £500
Don't disagree with you on quality vs quantity, but suspect the OP is looking for a more cost effective service on this occasion.