here are a few other possible choices mentioned earlier in post #3651 all of which should all fit the Grado cup style for around $20 or less.
for the record i didn't discover most of these myself, though read about them from other Head Fi members in this forum and thought it would be good to make a list,
- anyone who knows of other options please feel free to add to the collection.
Vivitar DJ mixers http://www.amazon.com/gp/product/B00NIZ88GC/ref=pd_lpo_sbs_dp_ss_2?pf_rd_p=1944687682&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B00NIZAUK4&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0SCSVDSDB6MB4NDA1KMQ
WeSC Unisex Matte Conga http://www.amazon.com/dp/B00AFON07G/ref=psdc_172541_t3_B00BQ16RCM
Sound Intone HD850 http://www.amazon.com/Sound-Intone-HD850-Lightweight-Stretchable/dp/B00ZK7M628/ref=sr_1_7?s=electronics&ie=UTF8&qid=1446910048&sr=1-7&keywords=Sound+Intone+HD850+On-Ear+Lightweight+Stereo+Headphones+black
also these (below) have been suggested and look great, though cost over twice as much at $49 and there is no guarantee (yet at least) that they fit the Grado style cups though it seems they should and could be modded to without too much difficulty.
Symphonized Wraitth 2.0 http://www.amazon.com/Symphonized-Wraith-Premium-Genuine-Headphones/dp/B00ZGNX8XC/ref=pd_sim_sbs_23_3?ie=UTF8&dpID=51Hx0Qw9ZEL&dpSrc=sims&preST=_AC_UL160_SR123%2C160_&refRID=0N6HQQPMC2K35AM5HE3A
Symphonized Wraith 1.0 http://www.amazon.com/Symphonized-Wraith-Premium-Genuine-Headphones/dp/B00LFVSKRS/ref=pd_sim_sbs_23_4?ie=UTF8&dpID=41oeg%2BLqRoL&dpSrc=sims&preST=_AC_UL160_SR148%2C160_&refRID=0N6HQQPMC2K35AM5HE3A
the aluminum bands/gimbals which hold their cups in place look fairly flexible and easy enough to set at the right distance but i'm not sure the pins which connect the gimbals to the Symphonized cups would fit into the hole on either side of Grado styled cups. also it doesn't appear that they are fused to the gimbals themselves, they may fall loose once the gimbals and cups are separated ? (i'm not sure) . if so there should be a way to solder or rivet it back to the aluminum gimbal arm, if need be
xylin6, thanks for the work in providing this list! I updated my Post 3452 to include your list, except for the Symphonized headphone, until we can verify whether it fits. I sent a PM to the member who wrote the review for Symphonized headphone here on Head-Fi to see what he might be able to tell us, and will report back if I hear from him.