Unless you are running a million dollar enterprise or a graphics developer team I really don't see any good reason for having a Photoshop, especially when there are lot's of work around to any problem.
Here I will be discussing some alternative approaches and softwares that can help you out from any Photoshop need with using Photoshop.
If you go on a search for a free alternative to Photoshop, this one will always be there in any list. And why not! GIMP is perfect in its own and there is a better version coming out very soon viz GIMP 3.0
Inkscape is also a really popular vector graphics editor. Only problem is, it's a vector graphics editor. So unless you are going to vector graphics in this you will find it really difficult to work with.
Krita is a manga and anime drawing tool, but of course it's not limited to that. It's not like somebody will call SWAT on you for making a logo on Krtia. It's simple, full of feature which could take your whole day to learn everything and it's beautifully designed.
Now given all of the options, this has to be the best and it's an Online Editor. Pixlr has got all of the option you might need. Ofcourse it's tiresome to do hefty task on this since it's an online editor, but it's something you should have a bookmark of always.