Breeding advice

Hiya! I am thinking maybe breeding our collie for one litter. What advice (or warnings) does anyone have for me?

How much does it cost on average to breed? And how difficult is it to sell pups?

I'm not 100% yet, it's just an idea I've had...And I am also not in it to make loads of money, just the one litter!

Why do you want to breed from your girl?

And if you are "not in it to make loads of money" what are you "in it" for?

I bred a litter of BC's April 2010, with all the health tests, extra food and worming it cost me 2100 pound, I sold 2 puppies for 450 pounds each, kept 1 and gave 1 away, so I was out of pocket by 1200 pounds! I'd had a waiting list of 8 people (incl myself) when I bred her, most dropped out for 1 reason or another and I had to advertise 1 of the pups, found her a good home when she was 9 weeks old, but if I'd have had a bigger litter I probably would have struggled to find good homes for them all (did have quite a bit of interest from pet homes, but I wanted them to go to sporting homes). The mum has proved herself in agility (competed at Crufts this year) and was from a good line of agility dogs and the dad from a good line of dogs working sheep, all health tests done, both have excellent temperaments.