You cannot "buy" an Australian visa in the traditional sense, but you can apply for one by meeting the requirements and paying the application fee. The process depends on your circumstances.
If you're interested in studying in Australia, you'd apply for a Student visa (subclass 500), which requires enrollment at an Australian educational institution, proof of financial capacity (around AUD 20,000–25,000 per year for living expenses), and English language proficiency. The application fee is approximately AUD 620.
For work visas, options include the Skilled Independent visa (subclass 189), employer-sponsored visas (subclass 482 or 494), or the Working Holiday visa (subclass 417/462) if you're under 30–35 years old. Requirements vary significantly by visa type.
For temporary residence or visitor visas, you'd need to demonstrate ties to your home country, financial capacity, and genuine intent to return.
The key is that while you pay an application fee, the visa itself is granted based on meeting specific eligibility criteria—you cannot skip these requirements by paying more. Visa processing typically takes 1–3 months for student visas and longer for skilled migration visas.
To determine which visa suits your situation, consider your age, qualifications, work experience, English proficiency, and whether you want to study or work. Each pathway has distinct requirements and costs.
I'd strongly recommend consulting a registered Australian migration agent (MARA-registered) who can assess your individual circumstances and guide you through the correct application process for your goals.