I spent the last three weeks rebuilding my market-making bot's data pipeline after Binance throttled my REST calls at 2 AM on a Sunday. That incident pushed me into the deep end of crypto market data relays — specifically the per-exchange subscription model that Tardis.dev and Kaiko use, versus the per-volume model that HolySheep AI runs. Below is what I learned, with hard numbers and runnable code so you can copy-paste-evaluate before you commit budget.
| Provider | Billing model | Binance spot trades | OKX derivatives | Historical depth | Approx. monthly (USD) |
|---|---|---|---|---|---|
| Binance official REST | Free, rate-limited | 1200 req/min | N/A | ~1 year ticks | $0 |
| OKX official REST | Free, rate-limited | N/A | 20 req/2s | ~3 months | $0 |
| Tardis.dev (direct) | Per-exchange + per-symbol | $50/mo standard | $50/mo extra | Full L2 book history | $100–$300 |
| Kaiko | Per-data-type tier | Quote on request | Quote on request | Tick-level since 2013 | $400+ |
| HolySheep AI relay | Per-volume (GB) | Included | Included | Full L2 via Tardis | $0.08/GB |
That table is the short version. The rest of the article breaks down why the per-exchange model punishes multi-venue strategies,