Connecting a Payment Link to a Landing Page for Business Validation

I have a business idea, and would like to carry out some customer validation before launching a website, marketing etc etc. Rather than asking people I know in this space “Are you interested in this, or would you pay for this”, I would prefer to collect cold hard facts and offer 3 tiers of customer added value; Tier 1 would be free, Tier 2 would cost a small fee for a one off bespoke offering and Tier 3 would offer updates to the paid offering, as market data changes throughout the year.

I am currently thinking of launching a landing page using something like Mailchimp or Sendfox, where it would just collect a Customer Name and email address. This would generate a Welcome email with a PDF attached containing the free general info I am offering. The email would also then have Google Form links to Tier 2 and Tier 3 offerings if the customer would like more tailored information, and these Google Forms would have a PayPal payment link attached to them for an upfront payment (I see Payable Apps can support this for example). Just in case it sounds a small bit scammy, I will only be sending this to people who know and trust me - but I am also conscious that these same people would like to support me verbally, so a better measure of their interest would be if they are actually willing to part with their hard earned money for the services I am offering.

Is this a good way to do this? Is attaching PDFs (10 mB) to an auto-generated email easy and affordable (would prefer to stay in the lowest bracket of pricing for now as this is literally just a business validation exercise). Are there other/better ways to do this? For example, embedding the Google Form and Payment links on a landing page? Is it best to only ever have 1 link on a landing page, or could I have links to the 3 tiered offerings? Best software packages to use to achieve this?Happy to hear any thoughts on this or other approaches I should research. Thank you!

This would almost certainly cause me to delete, possibly report as spam, even if I knew you. Attached PDFs are probably the #1 cause of viruses passed between people, so any reasonably tech-savvy person is going to be wary of this approach. Same for the blatant use of Google Forms. Can’t say either of these reek of professionalism that I would want to trust my money too. But I’m also a cynic who’s been in the industry for over 30 years.

If it was even just a SPA (single page application) site with your three-tiers spelled out in a professional manner with a GoFundme or Paypal link, I’d be more likely to support someone I knew, but that’s the minimum I’d need to support someone financially (with the caveat that the service is something I need/want).