shipping heavy amps - Canada to US?

What is the safest, easiest, and most reasonably priced method of shipping a pair of used, heavy (about 100# each) monoblocks from Canada to the US? I would really like recommendations on shipping them, but assuming the owner could drive them over the border, does anyone know what the owner would have to pay to cross over with them? Thanks.
UPS is out of the question. They wanted $146 to ship a passive preamp to England that USPS shipped for $28. I dealt with this problem recently myself as I was negotiating the purchase of a Musical Fidelity M3 from a seller in BC. Canada Post was the cheapest at that time. Why would he be charged for transporting his own property? Admittedly, I know nothing of new security measures since 9/11 but surly they were not intended to apply to personal electronics. Unless the amps are large enough to be considered a weapon. Don't laugh, I once had a custom agent at Kennedy airport spend about a half hour examining the Stax arm I had ordered from Japan. He didn't know what it was and this made it suspicious.
Canada post sucks! period.
Fedex and ups can ship but it's expensive.
If they can drive across the border, that's the best way. It's up to them if they want to declare the amps at customs. If they are smart, they will declare them. They will need a bill of sale from you to avoid paying customs on the full retail price. They could get away with a reasonably low sale price and pay the customs on that. If they go too low, customs will know (they'll google it).
The buyer should be honest that shipping was too expensive and the amps weren't worth that much.
Just keep in mind that Canadian customs are greedy...
I think Canada Post has a limit of 30kg. UPS ground does not include brokerage fees but UPS air does. UPS also has a "dimensional weight" that can double the cost.
Thanks guys so far, lots of good points (and some disappointing ones), but nothing to really run with. It seems that driving them across is the recommended best option, but both the seller and I are hours from the border, so with gas and drive time it becomes a less attractive option, and they would still have to be claimed and customs paid. Maybe FedEx Ground is the best? However, sounds like in addition to the shipping cost, there would still be duty and probably state sales tax to pay. Its too bad this is so difficult. Any other suggestions would be welcome.
The other consideration is the country of origin of the amps. If they were made in Canada or the U.S., or another country covered by the Nafta agreement, you won't be stuck with an import duty but if they're from somewhere else, you will. I learned that the hard way when I bought some English-made speakers from someone in Canada.
try Bax Global. They do not pick up at residences but your seller could probably drop it off at their airport location and of course you would need to have access to a Bax depot within a reasonable driving distance from your home...

Fed Ex ground is not Fed Ex - its sub-contracted so don't assume you are getting "Fed Ex" service. An alternate choice would be DHL. I heard from someone they had good success (and I don't mean necessarily cheap) but the package was handled professionally with accurate documentation and reasonable brokerage fees. Again this is just what I was told.
A must is to drive them over the border, then use ups ground, fully insured, double boxed. FedEx ground while a little cheaper, their insurance process sucks, with them not paying 95% of the time.
Thanks again everyone. The seller and I are currently exploring options that might be a win/win for both of us. I did receive a much better response when I called BAX today, compared to the information I was given on the website. On the website, it wouldn't give me a rate for their saver shipping, but when I called they were very helpful with that and in discussing brokerage. I agree with all who said it is easier to drive it across, based on my previous experiences. Too bad, this should be much easier.