He's afraid of spending money and still failing. He's spent too much time hiding behind excuses and now he's scared of being decisive and putting his money where his mouth is. That's why he's fishing around for bargains and talking about how important resale value is - because that way he can say we spent less than our rivals so THAT's why we win fuck all.
He doesn't show any conviction in the transfer market. I'm sure he's done plenty of research on Lacazette - either he's good enough for us or he's not. If he is, just spend that £10-15m extra to get him in an Arsenal shirt and to give us a chance of actually challenging for trophies. If he makes the difference and helps us win one of the big ones he will pay that back with interest. If he coughed up earlier he could have even had a full preseason with us and be ready to hit the ground running.