Do you think that social media is enough to validate an idea?
l have a lot of ideas, but not a lot of funds, so I can't buy a lot of domains, ads etc... to test my ideas easily.
Do you think that just asking a niche community if they have problem X and if they're ready to pay for a product solving this problem is enough to know if your idea is "good"?
If you get a few dozens likes/upvotes and positives answers, would it be a mistake to start working on the product/mvp?
Collect presales. Have people actually hand you money before your product is released. I believe that's the only way to truly validate.
Many people give positive feedback, but when the product/MVP actually comes around, end up being no shows.
Do you actually manage to get people to pay a new company for a product that does not even exist yet?
I would be really reluctant to pay personally, and I'm struggling to believe that a lot of people would do that.
Did you try with Nocodify?Did it work?
Yes - I did for Nocodify.
You don't have to actually charge them. You can just collect their credit card info and have it charge them the day the product is live.
Or have them pay to "reserve" their spot, or have them buy into the product with a discount. There are many different ways to collect presales, and it entirely depends on your business. The key is having them actually enter their credit card info to know that they are serious about wanting your product.
If you're solving a real problem. They will most likely pay. As long as your website looks well done and you have enough web footprint.