I have a maltesexshihtzu - she is a fussy eater as mcuh as I tried to get her to eat all types of food from the day I got her! She eats my dog (the little square foil tins) - which I get on special or at Big W - works out around 90cents each, so she costs roughly 90cents a day to feed (sounds cheap hey) she also gets the odd schmako, sometimes raw meat, etc. I would estimate she costs around $12/week max to feed.
Other costs:
Annual vet costs - needles, checkups $200-$300approx
Sundry medical stuff - wormiing, flea treatments - $200 approx

I wash and trim her myself - bought pet hair trimmers at Big W for around $100 - they have lasted for about 3.5 years and are now needing to be replaced.

My suggestions would be to go for a dog you feel will suit your lifestyle, Holly is an inside dog - though she spends a fair amount of time outside too - I chose her breed because she doesn't shed hair - so can be on the navy lounge no worries. She is an active dog when you are or a sleepy dog when you're not doing anything. She actually does her poos in the garden, I originally started putting her in the garden in my outdoor area when I was training her (rather than walk out to the back yard) and she just adopted the habit. Rarely does she wee or poo on the actual lawn!
She loves being walked too, but with a smaller dog, if you have lots of yard space, that won't be a requirement every day.