Brian Goulet just posted a mini-review of five "flex" fountain pens. A few of them fall under the $100 range.
Flex Nib Comparison: Noodler's Ahab, Pilot Falcon SEF, Noodler's Neponset, Stipula Splash, Omas Ogiva Alba 14k EF
My personal take is that none of them can compare to a vintage pen with a nice, flexible gold nib. YMMV. (I wouldn't turn down an Omas Ogiva if someone wanted to give me an early Christmas present! )
Flex Nib Comparison: Noodler's Ahab, Pilot Falcon SEF, Noodler's Neponset, Stipula Splash, Omas Ogiva Alba 14k EF
My personal take is that none of them can compare to a vintage pen with a nice, flexible gold nib. YMMV. (I wouldn't turn down an Omas Ogiva if someone wanted to give me an early Christmas present! )