My mum breeds whippets, she has 3, I have 2 and my sister has 1. We LOVE whippets. They are brilliant with children because they are humble enough to allow a (fairly confident) child to be 'top dog' or at least an equal! They are generally everso quiet and good in the house, but really lively and excitable outside it. They are also killing machines, mine mostly catch rabbits but have caught deer, squirrels, mice... anything that moves and they are on the hunt!
The costs are fairly minimul I think. I currently feed mine a dried food which I leave down all the time and let them eat as and when they are hungry. They also get lots of leftovers. One of my girls is a fussy eater and if she gets skinny I will buy her a couple of weeks supply of raw tripe to supplement her dried food. I would say that the two of them probably cost me in the region of £5 p/week to feed depending on if I buy a designer brand or a cheaper version.
Insurance... well my older dog is with petplan and thank goodness as she had a disc prolapse about 2 years ago which ended up costing around £1500 - all covered by insurance. Due to her age (9yrs) her insurance costs are high... around £32 p/month. However, when she was younger, it was more like £15 p/month. I would recomend having a whippet insured if you have one of the soft coated lines as they are prone to skin tears, especially when out hunting. That said, my younger dog is not insured at the moment as she has a tougher coat and is generally very healthy. I put money in a saving account for her instead.
Vaccinations I think cost me around £35 p/year p/dog including a full health check-up.
Other than that, the only other cost to take into account is buying them coats for winter. If yours are like mine they will go hunting in their coats and rip them to shreds Also if you are like me you will be addicted to buying them coats as well. Whippets will need coats in winter as they do feel the cold but you can get some very smart ones to show off in the park!
Whippet Bedlington X are very nice as well. Bedlingtons were one of the dogs breeds used with Greyhounds to create the whippet so you are crossing back to type iykwim.
In terms of buying, go to a reputable kennel club registered breeder and make sure the pups have been well socialised with people. They shouldn't cower away from you - just because they look ss if they should be nervous, doesn't mean they should actually be nervous iykwim. Whippet puppies should be confident, happy little souls attacking shoe laces and snuggling in arms and laps.
When training them, they are generally pretty meek and are most upset even by a raised voice, I would never raise a hand to one of mine - it simply isn't necessary. Some seem to be pretty good at learning tricks, others just don't really get it - depends on the dog. It's a good idea to start working on basic recall as early as possible as like all hounds they can be a bit trixsy about coming to call. Once they are 'on' something, their instincts kick in and they effectively go deaf so being able to get them back to you the moment you see the ears go up (tell tale sign) is a useful trick especially if you live near busy roads. My mother has hers trained to a dog whistle and practices regularly in the house to re-inforce the message.
Good luck, I would love another whippet puppy but two dogs is enough and I now have a baby on the way.