Like any manager, many times I had to talk to designers who came up with questions about salary increases. I’ll tell you how I see it from my side.
I would not recommend using an offer from other companies as a basis for salary negotiations. If you come with another offer, you are blackmailing the employer. Such a visit could lead to a broken relationship with management. Some managers treat this normally, they may even try to interrupt the offer, make a counter-offer. And someone will be disappointed in you forever.
If the employee is really incredibly valuable and there is no one to replace him, the manager will be quicker to meet. But about yourself, almost certainly, will think of a person worse than before. Is money the only thing that keeps us here? A person needs to pay decent market money without a doubt, but in good companies people work not only for this.
Another point that confuses me in the question – the phrase “lower class agencies.” Weak companies are often forced to pay a little higher than the market, because they have nothing more to lure people. In essence, with this extra money, they are trying to compensate for weak tasks and a weak team. Or high risks if it’s a startup. But is it really worth it? Do you want to spend a lot of time in the company of colleagues from whom you can learn little while working on boring tasks? If the designer does not have enough money right now, you can take a freelance project. Is it worth exchanging a good job for a little extra compensation?
I had a moment at the beginning of my journey in Yandex, when they really wanted to buy me into another company and offered a salary 2.5 times higher than I had. I am very glad that I did not agree – a year later the management of that company changed and the team was disbanded altogether. And in Yandex, my salary eventually overtook that offer.
This does not mean that the salary can not be said. If the market insists that you are more expensive, then with the management it is possible and necessary to talk about it. But only in the format: “I would like to earn more: how can I bring more benefits, how can I take more responsibility?”. And you don’t have to wave offers from other companies to do that.
Rule: if you value the current work and the relationship with management, then talk about raising salaries in terms of responsibility and benefit to the business.