Looking around it seems like letters are about 70 cents and post cards 40 cents. Wouldn't it be a lot cheaper to type up your on template/letter put your letter head on it with contact info and make a bunch of copies? Thanks.
It cost $0.50 to mail a letter. Add the cost of the paper, ink, and envelope. then add the time it takes you to stuff the envelope, address it, put a stamp on it, and drop it in the mail box.
Even if you save $0.15 per letter, how many can you do in an hour? 100? That's a whopping savings of $15. If you do 200 in an hour, you've saved $30.
You have to decide what your time is worth and what you want to do with it. If you'd rather spend an hour stuffing envelopes in order to save $15, it may not be the best choice but that's your decision to make.
@Nathan G. I couldn't have said it any better myself. Also @Beau Alesi , direct mail tends to work better when each letter is specific to the individual so saying Dear John, rather than Dear Homeowner. So if you can merge the fields that is a positive, but a lot of direct mail companies will do that for you no problem.