Meetup.com is very good platform to organize your meetups. I recently planned to organize my PHP meetup. Price is not too much, just 2 dollers/month for 6 month plan; $12/6 months (In Indian Rupees as per exchange rate, approx Rs. 720 as of now.)
Not a huge amount but still if you are serious about meetups, you can get 50% off on first billing. Just start creating your meetup group and when you reach to payment page, close the browser/tab. With in 2-3 days, you will get mail from meetup.com offering 50% discount, applicable for limited period. Grab it immediately.
Please note, in case you had not made your mind to start meetup gorup, dont try this trick. You get this offer only once and once it is expired or used, same trick will not work on your account.