Yes, indulgence can be risky and leave you with a hefty bill if you get bumped...
Can't see anything wrong with the clear reply from AT Mov - so Ginger Beer, your rudeness is unhelpful and misplaced. Take first the mote from thine own eye, I would moot!
Try looking at
www.opodo.co.uk for flights to LAS; as an example, I looked at 2-8 Mar 2008 and found a flight for around £420. With Air India and 'other airlines'.
www.ebookers.com found one for £670 with Iberia. Choose your dates carefully and book at the right moment and £400-600 should be possible.