Soo hope I don't get slated for this......I always found that it was ok mixing on headphones. I used to use a set Ixos DJ1001's which were designed by the company I used to work for. They had great detail for fine tuning problems in the mix. However I then had to master it on different sets of speakers to get that finished result that worked on all systems.
I always used to find my old Kenwood home hifi generic speakers were really easy to master on (Well as close to mastering as I got back then without paying for it to be done!) But that being said it was probably because I was very familiar with them.
I still haven't bought a proper set of monitors. I now use a pair of Monitor Audio Bronze B1's of a Old Denon 2-channel amp, and am very comfortable using that for all my mixing.
So what I think I'm saying is, it matters not what your tools are, just how familiar you are with them and how they work in comparison. Learn to use what is available. Master that step and you'll excel as your equipment is upgraded.