You only need the IDA Pro Starter Edition (589 USD, 32-bit files only) or the regular IDA Pro version for a single architecture (1129 USD).
Even so, IDA comes with decades of RE experience baked into its heuristics and analysis features. It's quirky, yes, but as a professional tool it's also worth the money.
Nonetheless, thanks Google for lowering the bar for entry into professional security work!