Was sad to leave - Credentialing & Billing Operations Amplifon Employee Review

I had been with the company for several years and moved into three different departments and in the end I was still making less than $17 hourly (even with yearly reviews/ department move pay increase) however I thought I was making industry standards and didn't focus too much on the pay...that is until we had a new hire in the same role and I had found out the new hire was making $2 more than myself (of course pay is based on education/experience in the field however since I myself trained this person in and we got to talking - the new hire had less experience and same level of education). I felt underpaid and decided to look for a new job and as I interviewed with more companies (Fairview, North Memorial, etc) I found out that these companies were paying entry level much more than what I was making after 3 years (beginning wage $22 and up based on experience) doing exactly the same thing. I was sad to leave such a great company but ultimately the pay I was offered elsewhere was something I couldn't turn down and probably would've only made if I stayed another 10 years. The only real con was the pay, and maybe less room for advancement. I couldn't see a bright future there for myself. Unless a manager/supervisor was to step down, the growing stopped. There can be no moving up to that next level if the next level is occupied or non existent.