I bare metalled/primed/painted/lacquered my Bars, seat post and a few other bits and bobs. I used Halfords Gloss black rattle cans , grey primer and clear coat (about £7-8 each for a large can) .
Take your time and you can get a perfectly acceptable finish. I applied about three coats of primer, left a day, rubbed down with 800 grit wet and dry, then put on about four coats of Black. You can flat out any crap that gets in the paint in between coats. (leave 20 mins between coats).
Once the top coat is touch dry, then apply about four coats of clear. You can flat off the black coat before clear, but i didn't bother and the results were pretty good.
When applying the paint, i found the best technique was to dust it on first, then a smooth side to side action in different directions to get an even coat. Hold can about 20 cms from the frame.
Finally, if your'e not happy with the finish, you can lightly flat the clear with 1500 grit, and use T cut or similar to get a decent shine.
For smaller parts, I put my oven on about 80c and baked for an hr to harden the paint.
I think i did the bars and seatpost with one large can of each, so it cost about £22, just to give you an indication.
What i achieved, to give you an idea..
Hope that helps
PS- worth checking out prices of powder coating, some of the other guys will have a better idea than me