If you are looking for monthly basis sales/subscriptions to setup it you must have premier/business account on Pay pal.
for more details,you can chick here
You can Setup PayPal Subscription & Recurring Payments, that means the buyer will be billed Monthly/Quarterly/Semi-Anually/Anually etc.
So you basically have to choices that you can setup subscription buttons and place them on your website or create email links and send them out to your customers. Here are the steps you need to take once you have a PayPal account setup.
Login to your PayPal account
Click on the Merchant Services tab at the top
Then under the “Create Buttons” section, click the “Subscribe” link
If you’re setting up payment via email, make sure you change the last option button encryption to “NO” otherwise you won’t get the email link. Also, the email link is really long and will break if you just paste it directly into your email. So what I did was use a free url converter called TinyURL and created a much smaller url which I then included in the email.
Shortly again:
Go to Merchant tools – > Select Subscriptions & Recurring Payments option – > Fill your require details there – > Check No option for Button encryption at the end – > On next page copy paste from Link for Emails and PM.