WZ is correct in that modulars cannot meet Snell standards, so DOT is the only certification that you’ll find on modulars in the US. I also realize that they cannot be worn on the track. However, “the chin bar is really just for show and doesn’t offer a significant amount of protection really over just having a half helmet with a full face shield” is just plain wrong. Here is the SHARP(British government rating) page for my modular, the Nolan N-102, http://sharp.direct.gov.uk/testsratings/nolan-n102. Note at the top, the percentage of impacts where the face guard remained fully locked is 100. To say that a FF offers the maximum amount of protection is fair, but to take the next step and essentially say that the chin bar is nothing more than cosmetic is giving incorrect information.
As for sub $150 modulars I can’t make any suggestions as I don’t have first hand experience with any. My N 102 which has been discontinued can still be found, lowest price I’ve seen is about $175 for the solids. I can tell you that I now ride more frequently with my FF for the two reasons that WZ mentioned above. The modular is significantly heavier and noisier(and my Suomy FF has a reputation for being noisy itself). However the Nolan still gets taken out and I never feel that I am compromising my safety in any way.