NeoTat classic is 250$ new. However on your budget and need more at once I would get a national coil machine set up as a liner and go unimax for a shader. I think you can do that for about 250$ with the left over 100$ you could get a stealth ( the much loved copy of the Swiss ) or you could get another unimax coil. ITS sells machines for about 50$ that aren't terrible, some new coils and springs an they are halfway decent. I have seen a few aluminum machines on eBay that run pretty cheap too, just know that the springs and coils are most likely less than garbage.

Best o luck to you and stay positive. It will mean the world to your kids to see you strong.