I have updated one of my models that compares value versus market pricing to included APN, plus some other overseas listed and resourced silver developers/producers.
As of Fridays closing prices the best entry price determined by comparing the amount of Ag or Ag Eq you gain access to, in the ground, when you invest $1,000 are BML, then HYMC, then MMA.APN, you ,mentioned, if I have the company right, is expensive compared to the others by a long way.
BML is the most de-risked and on target to be first to mine. HYMC is interesting as its resources are in Nevada and huge and predominately in tailings. MMA is a standout too - it has a big chunk of metal in QLD and recently showed it has a resources about 70% of the size of IVR or ARD and BML in the shallows (before the larger resource needs to be mined underground).
This is only one measure of course, but it provides a glance and a way of sifting. DYOR on the features and benefits of each company and their projects.