You can buy an HJC helmet cheap, Snell 2000 certified, and they are good helmets. I have a CL series, and will be probably be upgrading to the new carbon fiber one when I get some money.
You don't have to spend $500+ to not be 'skimping' on a helmet.
To answer your question, dont get a modular. They have been proven to open up in an accident, and then your face is protecting the inside of the helmet.