If you don't want to go for PPC you can go for SEO only. Its much cheaper than PPC. You can do just some tasks to do marketing for your company as- Directory Social Bookmarking Social Networking Articles Blogs Video Submission Forums yahoo and Other Answers
SEO is not cheaper than PPC. SEO takes time, resources and effort and is not a guaranteed traffic method
SEO is not necessarily more expensive but you are correct that it also can be in terms of time which as we all know is money. I would recommend a combination of both of these techniques but if you are just starting out doing SEM I would begin with SEO.
seo investment is stable traffic in long term, ppc is volatil traffic, you have it if you spend $$, i use both of all , but i focus 90% efforts on seo
PPC is cheaper in actual dollars, but SEO is more expensive in time spent. If you're doing some type of direct marketing where you're selling a product then get some kind of conversion tracking and you can get a profitable campaign going. If you're just building awareness of your company then social media is always good. Create a Facebook page (don't spam your fans) and offer an incentive to Like your page.
If you spend time everyday working on your Social Media Optimization. It takes time to build a name for yourself though.
As stated before: SEO is not cheaper than PPC. SEO takes time, resources and effort and is not a guaranteed traffic method just need to use them and you can utilize google base as well if you are selling products and services...
try to find more popular sites related to your niche. and contact site owner to put banner ads of your products on monthly basis. you will get more benefits.....