Che, I totally get it. When I first got here from Buenos Aires I was watching every peso too. Worked from free wifi for two months straight. Here's what actually works.

The public library on 25th Ave. This is the hidden gem. AC, quiet, free wifi at 15-20 Mbps, open 9 AM to 7 PM. Almost no tourists know about it. I spent weeks there.

Parque Fundadores has city wifi. Speed varies, 5-15 Mbps. Fine for email and Slack, forget about video calls. But the setting is nice if you don't need heavy bandwidth.

Starbucks on 5th Ave. Look, I know, but the wifi is consistently 25-30 Mbps and there are outlets everywhere. Buy a coffee every couple hours ($60-80 MXN each) and nobody bothers you.

Super cheap hacks: some OXXOs on 10th Ave have tables, AC, and wifi. A $25 MXN coffee and you can sit there for hours. Nobody cares, seriously. Hotel lobbies on 5th Ave usually have open wifi, just order a drink at the bar ($80-150 MXN) so you're not just freeloading.

Cheapest proper coworking is Selina at $150 MXN/day ($8.50 USD). Otherwise, Ojo de Agua and Ah Cacao are the most nomad-friendly cafes, budget $100-150 MXN in purchases per session.

Some tips: always have your phone hotspot ready as backup. Download all your docs before you go out. Use noise-canceling headphones. And do video calls from home, save the free spots for focus work that doesn't need stable bandwidth.

Honest math though: Nest coworking at $4,500 MXN monthly divided by 22 work days is about $205/day. Cafe hopping costs $150/day in coffee plus unreliable wifi plus no phone booths. At some point the coworking just makes more sense. But until you're ready for that, the library is your best friend.