Earlier quoted context omitted.
You can save further by patching air chambers with other air chambers, or better yet fit a ring of old air chamber between you tire and the air chamber, creating a thicker wall that it's harder to penetrate by debris, glass, nails, etc. You can get your tires pumped for free at most bike shops, gas stations, public bike repair stations. Use your saved up 50€ for beers or better yet give it to someone else so she can…
Is 'air chamber' the literal translation from French? I like it better than 'inner tube'
And so on and so forth.