Download a Trial of CS6 see how you like it. That is the only version you can get a perpetual licence for. Standard version is $700 extended version$1000.
Download and install the CS6 trial from Download CS6 products
You can use it for free for 30 days without entering a serial number.
You can purchase a serial number from Creative Suite 6
Just bear in mind that CS6 is the end of the line for perpetually licensed (pay once, own forever) products from Adobe.
CS6 is 3 years old and no longer being upgraded. What you see is what you get. It still has relevance in today's market since it's only just been discontinued. However, as time passes it'll fade into obscurity.
All Adobe's development efforts are being put into the Cloud version now.
Michele, what sort of work will you be doing with Photoshop? CS6 is obviously a very powerful image editor, and will do most of what you need regards photo retouching and manipulation, but if you want to do more, the gap between CS6 and CC is ever widening, and will continue to do so. CS6 Extended will cost you about $1500 (depending on what country you live in). That would give you three years of subscribing to the $10/month Photoshop/Lightroom Photography deal, and the gap between the products will be a lot wider by then.