Perhaps the
Sound Blaster JAM from Creative might be closer to the PX100. That's a surprisingly good pair of inexpensive headphones, especially for the price and form factor.
While I barely remember the PX100, I still have an old Alessandro MS1 that works just fine. If portability isn't an issue, maybe you could consider the Alessandros or entry-level Grados. Admittedly, their sound signatures are very different. So you might want to find a way to listen to them first.
Maybe check out
headphonezone.in and/or Amazon and see if they allow free returns for a refund or exchange; in case you don't like the sound signature.