I'm a little late to the game on this post, but thought I'd throw my two cents in.
I really wanted to start with as little money as possible, in part to really learn the process and in part because I was nervous about spending money before I understood, but I also wanted to be sure I was taking action. We just started about 6 months ago.
I started hand writing yellow letters. It would take me a full weekend of writing in my spare time to do 50 letters (with envelopes and stamps).
So after a couple weekends when I didn't have spare time I decided to automate and this is when I got serious about things. I use Google Docs for everything and found some good hand written fonts, pulled all the yellow paper out of their tablets and did some mail merging. I was able to get an envelope template for Google Docs, also. I printed everything on my home printer. This worked well - I could get a couple hundred letters done in spare time on one Saturday or spread the job out after dinner during the week.
As of last night my off-brand ink cartridge isn't recognized in my printer so I started looking at direct mail options. It's $30-$50 for a new cartridge and I'd have to leave the house or wait for Amazon's 2 day shipping. That was the impetus I needed to get over my fear of spending too much money and start looking at what others were doing so I'm now reviewing Click2Mail and a couple others. I didn't keep close track of the cost for paper and my printer ink, but at first glance it's looking like it's about the same whether I do it myself or go to a mailing service and the mailing service is going to save a lot of time and allow me to stick to my mailing schedule which is an extra plus for the business.
I wouldn't change the way I did things, going slower allowed me to think through the process and learn some things. Along the same lines, I intend to hire a personal assistant in time, after I've done some of the work myself so I understand it.