I'm the only one of the three of us not tattooed (wife has 2, 20 yr old is about to get the 9th).
Where you have it matters a bit. Consider if you want to be able to cover it up or not (or if you want it as a chat up line I guess). The higher up the arm/leg the easier it is to cover up, likewise shoulders are harder than middle of the back if you're a vest wearer. This is a double whammy, not only will it be seen by more people if it's somewhere you never cover, but it'll need more care to keep vibrant if it is colours as they will fade thanks to being out in the sun unless taken care of. The other half of where you have it is that the closer the skin is to the bone the more painful the process will be. This all depends on how much you care about the pain, and how susceptible you are to it, my wife's first was a large tat centred down the spine. She was perfectly happy with that. I've heard the inside arch of the foot is the most painful location, possibly the ankle.
Tattoo artists are apparently the last of the great tax dodgers so cost wise will be a mix of time and agreed price (probably based on an estimate of time) The shop the 20 yr old is about to go to charges £70 per hour I believe. Find art you like, look at their portfolio, make sure you are happy with the studio before you use it. Some artists like to draw the design first (my wife's was like this) and can create the art for you, others want to have the picture done. If you have a solid idea of what you want a good tattooist shouldn't have a problem replicating that, although they may suggest variations based on their knowledge of the process (my wife's second was a sleeping dragon drawn by an artist friend. the tattooist reduced the original art for the location and suggestion colour changes based on the amount of black that was involved.