Going to respond to the original post. Had this big comparison on programs and such and bleh. In the end, it's really up to you and the work-space you're most comfortable with!
My first suggestion is to go download the trials to the programs everyone is talking about here: Sai, Photoshop, Manga Studio. I think they're all for a month so you have time to really play with them and see what you like. Head over to youtube as well. There's alot of tutorials and nifty tips to help you explore them even better and maybe learn of new features you never knew.
As per the following, some of it is opinion and some of it concerns price. Seeing that you're on a budget, it's certainly something to think about!
You started with a mention on Paint Tool Sai. This one costs, currently, $43.00 and it certainly is a powerhouse of painterly bliss. I used to use it a lot for art pieces because on the upside it has this wonderful water-paint tool to blend things together so dreamy. It's ink lines are nice and smooth as well. (more on that in the photoshop section) On the downside, dealing with adding typed text sucks royal. Great for arting, a pain in the butt for comicing. This is why it's collecting dust on my hard drive.
For Comics with Paint Tool Sai, it's a good idea to snag something like Photoshop. I think on the creative cloud it is 10$ a month for this industry standard. PS is is used by professionals and can do so much more than just ad text. Oh my goodness, I use it so often to process the raw files from my nikon into wonderful sharp photographic wonder. On the art side, however, the brushes are extremely customization, downloadable, and if you're wanting effects it's the absolute king. The reason I don't make my comics in it is a simple one --- they're hard to ink and the blending sucks. If you're wanting an oil painting effect, than who cares. If you're wanting to smear two colors into buttery bliss, then you better look elsewhere. With the inking, I also had a good deal of issue with staggering on the ends of my strokes. Not a big thing, but drives me up the wall. Ended up purchasing some added brushes from (I'll find his name if you need) and it helped a little. But note --- you can very well make a comic completely with photoshop and be pretty darn good.
Lastly we have Manga Studio which retails at $47.99 for the standard version. So, this is what I ended up going with for my comic. It lacks the watercolor tool of Sai and doesn't have the fun filters/text tools of Photoshop. What it does have is a whole bunch of other optional tools that can help you streamline your work. Just because something is easier, doesn't make it cheating. There is a prospective tool (Rumor has it they are adding that to Sai eventually) as well as a poser (to make 3-d human references. I think there's a free program for this online.) and even more tricks. It has the smooth lines and ease of Sai, as well as a very very customization set of menus. Actually, to me, it's like Sai if it was designed for making comics. I miss my watercolor brush, but the blendy ones have come through so well. Sai also has a text balloon feature that allows you to make your balloons with a flick of a brush. Unfortunately, there is only one style of balloon (with either thought or say tail which you can add how you like). It's got several different kinds of color pallets to help you blend and pick more easily. I would love to eventually see it get more text options for greater, well, options. To make spookier/wavier Oooohhh sound effects and the like which I do still need Photoshop for. It also has a huge preset load of screen-tones for manga which are fairly easy to use for those who wish.
Honestly, I'm happy with all three programs for their different uses. For comics specifically, I have to pick Manga Studio as it's just made for it while still carrying the blendy and inky art tools of Sai that Photoshop lacked for me. It helps keep me in order and allows me to spend less time switching between programs and more time actually producing the product I want.
Having more tools is not lazy. Having more options is never a bad thing. What matters is how you use them, and the story you create. It matters that you are enjoying the process of making what you are and are having fun with it. What you use in the end is up to you and you need to be happy with it. It may not be the 'right' way or the 'standard' but if it works and makes you happy, go for it. I work in a print shop and have had people make birthday cards in Microsoft Excel of all things but somehow, they made it work. I have no idea what sort of comic you're making.
Download the trials. Use the crap out of all of them while you have 'em and see what is going to make you the happiest, and work for you the best. There's alot of discussion in this thread so far with alot of opinions, but also alot of decent advice. Explore and choose what you want. And realize that you're not limited to one thing forever and should never let yourself be. Never stop exploring and learning new programs, techniques, etc. 
Better stop now. Going into weird inspirational pep-talk mode. 