You're right, I guess it's relative. But even still with your scenario, I would say they're "more expensive" but still not "expensive", if you catch my drift.
The whole expensive vs. not so much thing is truly all relative. I see some here who are scrimping and saving and trying to squeeze every nickel until the buffalo screams. Earlier in my life, when we had kids at home, there wasn't the disposable income that allowed me to do the things I can do now--when I'm an empty nester. I remember that I was about 38 when, for the first time, we ran out of month before we ran out of money.
Now, I have the income to do what I would never have been able to do 20 and 30 years ago.
Nonetheless, I still see a $7 Gamma Seal as expensive. I could get a normal gasketed lid for maybe $2 or $3, and it will work--it's just not as nice as a Gamma Seal lid.
Now, having said that, again it's relative. What you value, in a lid or in anything else, is your own concern, no one else's. I recently spent $61 in nuts and bolts (1000 nuts, 500 small bolts) to make some trays on which I can place cast bullets prior to powder-coating them. Many would say I'm nuts (sorry
), but it's a hobby and I am trying to perfect a system for doing them. Succeeded, as it turns out, after some other tries that failed.
If this brewing thing keeps going well, perhaps at some point I'll go to an electric system, perhaps with pumps and so on. When I can consistently brew great beer, maybe. I can afford to do that if I can convince SWMBO to do it--but she's pretty tolerant of my hobbies, especially those we can consume.
Hats off to those who are still scrimping to make their brew systems and recipes work. Been there, done that, I have a lot of respect for that.