All you need is to buy a region-free DVD player (available through online retailers) or to set your computer to Region 2 and keep it there.
Then go to Amazon UK.
The pound is currently at $1.56.
These are some sample deals currently available:
The Jeremy Brett Sherlock Holmes (complete): £19.67
The complete Inspector Morse: £42.18 (here you pay about $80 for a set of four episodes)
The complete Father Ted: £14.99
The complete Red Dwarf: £22.47
The complete Planet Earth: £16.99
The complete Cracker: £15.67
The complete Jeeves and Wooster: £13.97
The complete A Touch of Frost: £50.27
The complete Hamish Macbeth: £12.99
I have bought a number of items from them, and I've never had any problem except that I have to wait about six weeks for my shipment.