The best tattoo designs for sale have to be the ones that are exclusive and unique.  I mean you can probably find the same tattoos in most tattoo studios, so the chances of somebody else sharing the same design is very high.   This might not be an issue for some people but for me it is.  Anyhow, nearly every time you go to get some new ink the tattooist needs to draw up the line drawing (stencil)  the ones I know charge an extra fee for this service.  Most of us do not know this because it is hidden within the final cost.   I have come across a number of websites offering the tattoo design with line drawing so I would assume the tattoo artist would have to give you a discount for the line drawing seeing as they don't have to draw it up themselves.

I would much prefer to buy a tattoo design off a website now then pick one out at the tattoo studio.  For one thing you can look for the tattoo at your own leisure and also its much more practical to walk in to the shop with the tattoo designs in hand and with a line drawing already made up.