Here are some of the current agility equipment sales on ebay
 

Agility Dogs Jump 4 Joy

This ebay shop has very reasonably priced jumps and weave poles that won't take up too much space in a small garden.  They also do a range of agility clothing such as sweatshirts and polo shirts in different colours.  They are embroidered with a logo of a border collie jumping a hurdle.  The sellers have 100% good feedback and come highly recommended from their customers. 
Latest update: John tells me that they can supply jump cups at good prices so it's really worth having a look at this shop.
 

The current auctions from Agility Dogs Jump4joy are shown below

John's Agility
The equipment from John's Agility on ebay is also reasonably priced and you have a choice of training hurdles which you can buy singly or in a pack of three.  Other equipment is also on offer and most of the items are, "buy it now," which means you can buy straight away from the ebay shop without having to wait and see if you've won the item in an auction.
 

The current auctions from John's Agility are shown below

Grange Pet Centre
This ebay shop has a very good record with ebay.  They do some tunnels and the mini see-saw shown on the right, as well as some very basic hurdles and waeve poles.

The current auctions from Grange Pets are shown below

Surepets

This supplier from ebay has some inexpensive items of equipment.  They do sell a see-saw but as with all equipment make sure it's suitable for your dog.  The see-saw currently on sale, as at 28th June 07 , is smaller than the minimum sized one used for licensed Kennel Club competitions but it could be very useful for basic training.  If you have a great, blundering mutt like Jamie this would be no good at all.  He'd topple it at the first go.  A little light Border Collie like Sasha would be fine, although I'd want to make sure it couldn't topple easily under her weight. 
 

The current auctions from Surepets are shown below

Dog Agility Equipment from ebay
Do make sure that if you buy equipment over the internet it's  safe for your dog.  Jamie can topple a cheap see-saw and he's gone through the A-Frame at training classes.  (Bear in mind that he's the canine version of Frank Spencer).  Please also bear in mind that I'm just getting to grips with putting things like the live listings shown below on the website so you might get something like boxing gloves as well.  One day I'll be a super duper websmaster and get it all right.