Go for the interview. There could be other things that make the salary increase not worth it...or you could decide that it's a good fit for you & worth a change. If your job is a dime a dozen, then higher turnover is probably expected.
If you get an offer, but want to stay at your company, you may be able to negotiate a raise based on your offer from the other company.
The company will ALWAYS do what's best for the company. You need to do what's best for YOU.
You have to work either way. Seriously it's better to have more money for the work you do. You don't owe your company anything. Move on in good conscience.
My 30% raise this year was pretty life changing. We were fine before but now it's just less stressful. Water heater issue? Meh. Car issue? Meh. I'm lucky that I like my job and make good money. People don't have the same allegiances to employers any more. Go for it!