It might not be that you don't have enough money. You might just be passing up some options, some free and some inexpensive.
Breeding nets are really cheap actually.
See? Skip a lunch and you can afford this.
You really don't need flowing water if you want to keep the fry. That means you can keep them in a bowl, pot, bucket, or whatever. Let me explain. I had an impulse buy one time and I ended up with a Blue Lobster. I had two tanks, but only one filter. Basically I ran the filter on the Blue Lobster tank all day, except for when I got home from work for about three hours, when I ran it on the fry tank. The fry aren't going to make that much waste, and swapping the filter over for a few hours should suffice as long as it runs the entire volume of the tank/bowl/bucket a couple times over per hour.
Take river rocks, which you know are safe. Since rocks aren't flat, they won't sit flush against one another and create crevices for the fry to hide in and grow up. Careful though, as rocks can sometimes raise pH of a tank. That's why I said river rocks.
Good luck.