I don't know about you, but I cannot stand it when people smell badly. Whether they haven't put on any perfume that day, or didn't shower or whatever. It's just a bit rubbish when they don't care about personal hygiene or smelling nice at all.
I never leave the house without spraying something on. Even if it's just a bit of the Playboy 'Lovely' body spray (which is better than Impulse as that's horrible) and still fairly cheap. That's pretty good for when you're in between work & gym & home and need something quickly.
If I'm going out I always use either Britney Spear's 'Curious', or Dior's 'Forever and Ever'. During Winter I tend to use Hilary Duff's 'With Love'. I prefer spraying perfume on my clothes as sometimes you may break out into a rash if you put it on your skin. I think the best places to put it on it your cardigan/skirt/and a bit in your hair. Not too much so it's overpowering but enough so that when people walk past you they catch a whiff of it and take note.
You can never really have the excuse of 'I don't have any money' in order to buy some nice perfume or deodorant. Personal hygiene and being well presented at all times is extremely important - especially if your out on the town. I have some friends who seem to never put any of it on and it's really frustrating cos you can't really mention it as it's a bit rude. I purchase mine at Myer in the Bourke Street Mall. I use my Myer One card while I'm buying as you get discounts with the card and you also get notified of Super Secret One Day sales. If Myer is still a bit out of your price range - try Priceline or even Target. They are much cheaper and pretty much the same thing.
Or, you could try and buy online. Online shopping is the best. It's quicker than retail shopping, you don't have to put up with jerks in the store or at the counter. You can also get more discounts if you get them online. Sign up with your favourite stores e-newsletter so you are notified of special sales. Keep track of the 'secret codes' they use so you can use them when you buy. This site is great for that. These sites are also good if your looking just for perfume    .