Research! If your financial budget is tight, maybe you can be more liberal with your time and patience?
I'm cursed with a lot of ideas, many of them that I think are great, that others don't think are so great. Before I learned to validate my products, I became too enticed by building first, validating second.
Now I always validate first. It's hard to find the time and patience to do it sometimes, however validation always pays off down the road. Recognize that time and patience are valuable resources that are usually only limited by your own drive and desire and use them to your advantage!
Some suggestions -
-Search relevant niche forums to see if people are asking for what you're offering.
-Search relevant niche forums to see if people are asking questions that show they're having the problem your product is going to solve.
-Talk to people in your target market to see if they are experiencing the problem you are solving, or are experiencing some form of the problem you are solving, then adjust/adapt your product accordingly.
-Monitor places online where your target market hangs out and answer questions with a genuine desire to help, pay it forward so that when you do ask questions, you're seen as a valuable contributor to the community, not just someone looking to take from it.
Always happy to discuss further on a call and good luck!