Sadly, no: you'll almost certainly burn it, faster than you think.

Anthropic recently (within the last few months) gave out what amounted to around $70 CAD im free credit. I rationed it slowly, spending maybe $5 in a month, using it a few dozen times to allow a Haiku-based task to finish past my usage window.

When Opus and Sonnet 4.6 released, I made the unfortunate mistake of "experimenting" with them on some work that couldn't be thrown away. I hit my timed usage cap, allowed Claude Code to consume 'extra usage' credits, and... nearly vaporized the entire credit balance within a couple tasks.

I understand that Opus and Sonnet are (considerably) more expensive than Haiku, but watching money burn by the dollar, in real-time, was enough for me to turn off extra usage entirely.