Last year I flew my bike into Denver and back from Vancouver and that was about £1000 to £1250 each way. The flight back from Vancouver to Manchester did not require a crate, it was just tied down to a large plate, wrapped in cling film and the plate was then fastened to the hold floor. I think the service operates a couple of times each week, I got this through HC travel who in turn used Motorcycle Express, but I ended up sorting details with Motorcycle Express so I'd recommend going straight to them. I think the charter airline they use fly in & out of Calgary as well as Vancouver and if you really want you can fly on the same plane as your bike, but I've no idea how much that costs. Motorcycle Exoress organised all the paperwork.
Air Freighting the bike from Vancouver to the UK worked really well, I supervised the tying down of my bike at Vancouver as the guys there deemed less bike savvy that the unloaders at Manchester were excellent and pointed out some cosmetic damage, but that had been done on the flight out. I used James Cargo to airfrieght to USA (Denver), that was less straightforward, needed crating which James Cargo did but there was some minor damage possibly done as part of the journey was by road. The insurance I paid for seemed totally useless but it didn't cost that much to fix. Crate disposal at Denver should have cost me a bit but they were so interested in what I was doing they waived the fee. I needed the EPA authority for a temporary import to the USA which I did myself, it's simple, and James cargo did the other paperwork. Coming back, Manchester airport insist on using a shipping agent which can cost £100 or more, especially if it's at weekends.
If you are very precious about your bike I'd say think twice, but if, like me you aren't too worried about the odd scuff mark then good luck.
Just thought I'd mention, USA customs were no problem, except they were only open 9-5 5 days a week and their office was some distance from the airport. This may be peculiar to Denver but I had to wait a day for a bank holiday and then it took a couple of hours to get to the customs office and get the paper work stamped then a trip back to a cargo shed near the airport to pick up the bike plus an hour or a bit less to uncrate it, so a good job I had a bit of slack in my plans!
