The following is Google AI’s answer to this question

No, cheap provisional patents are generally a poor investment because a poorly prepared or “cheap” provisional application offers no real protection and can be detrimental to your patent rights, potentially leading to loss of patentability or reduced value for your main patent. While a provisional application can lower initial costs, it requires significant investment in a detailed non-provisional application within a year and can even delay the overall patent process, which is often disadvantageous for startups. A well-prepared provisional application is crucial for securing priority for later details, but this level of quality is rarely achieved with “cheap” filings. 

Why “Cheap” Provisional Patents Are Risky

• No Benefit, Significant Downside: A poorly prepared provisional patent application can be worthless and may even cost you your patent rights by demonstrating a lack of preparedness or limiting what can be claimed in the subsequent non-provisional application. 
• False Sense of Security: Investing in a “cheap” provisional can lead to a false sense of security, as it may not adequately describe the invention’s essential components, leaving those features vulnerable to being patented by others. 
• Costly in the Long Run: While the initial filing fee for a provisional is lower, the total cost includes the subsequent, much more expensive non-provisional application. You also risk wasting the entire application fee if you fail to file a complete non-provisional within the 12-month window. 
• Delaying the Patent Process: A provisional patent application’s primary function is to extend the time to file a non-provisional patent application. This delay is almost always detrimental to a startup, which ideally wants to get its patent as quickly as possible. 

What to Do Instead

• Prioritize Quality: Whether it’s a provisional or a full utility patent application, quality is paramount. The application must contain a thorough description of the invention. 
• Consult a Professional: Hire a patent attorney to prepare your application to avoid legal pitfalls and ensure the invention’s key aspects are adequately described. 
• Consider a Direct Non-Provisional Filing: For startups and independent inventors, filing a complete, well-written non-provisional patent application directly is often a better strategy than attempting to save money with a poorly prepared provisional. 
• Understand the Provisional’s Purpose: A provisional application is a useful tool to secure an early filing date and provide time to develop an invention further before committing to a formal patent application. However, it must be sufficiently detailed to support the claims made in the later, non-provisional application.