I got my current commuter bike (a Trek Hybrid) off ebay for under £70.
Got a local bike recycling charity to check it over and fix the gears which took the total price to £80.
Been commuting on it for 3 years and now have a better idea of what I want from a bike.

If you haven't already bought the Falcon, try your local bike recycling charity: The Bristol Bike Project (I can't post a link coz I'm new here)