Free, if you're willing to be self-directed
Stepik hosts several free, Russian-language courses with real depth — "Машинное обучение" (72 lessons, hundreds of reviews) and "Введение в Data Science и машинное обучение" among the most established — video lessons plus graded exercises, with a free completion certificate.
The Yandex School of Data Analysis (ШАД) publishes its actual machine learning handbook and course materials free at education.yandex.ru/handbook/ml — this is the same material Yandex uses to train its own ML engineers, not a simplified public version.
Business-oriented, no-code-required (Skillbox, Netology)
Skillbox's "Нейросети: практический курс" runs about 3 months (~$750 at the discounted rate seen at time of writing, with a 12-month installment option) and focuses on applying existing AI tools — text, image, video, automation via n8n, AI coding assistants — rather than building models from scratch.
Netology runs several shorter, role-specific programs instead of one broad course — "Нейросети для бизнеса," "для маркетинга и продаж," "для анализа данных," and a from-scratch ChatGPT/prompting course — aimed at people who want to use AI tools well in a specific job, not become an ML engineer.
Technical, developer-oriented (OTUS, GeekBrains, Karpov Courses)
OTUS's Machine Learning tracks assume real Python and math background and go from a "Basic" tier (from ~$95/month on an installment plan) up to a full 12-month specialization (~$1,700), covering PyTorch, transformer architectures, and MLOps rather than tool usage.
GeekBrains and Karpov Courses sit in similar territory — GeekBrains' 12-month "AI Specialist" program runs roughly $1,500+, while Karpov Courses' machine learning programs range from about $350 for a focused track up to a joint master's degree with HSE at roughly $2,450 — both assume you're aiming for an actual ML engineering role, not general AI literacy. A practical filter: if you want to use AI tools better at your current job, the Skillbox/Netology tier is the right depth for the price; if you want to become the person who builds the models, the OTUS/GeekBrains/Karpov tier — or the free ШАД material, if you're willing to self-study rigorously — is where the actual skill gets built.