Welcome to GF! I had to approve your thread (sometimes they require approval, not that often) which is what caused the delay. Leopard gecko eggs are very hardy. I've had a couple of instances where my incubator was accidentally shut off for a few hours and everyone hatched out OK. There's no guarantee, but a good chance of success. If the eggs don't hatch, it could just be the luck of the draw. It sounds as if you need to get a decent incubator because temperature fluctuations can result in a higher number of birth defects. 89 is a bit high and I would recommend 88 (you should still get males). I recommend you either get a hovobator plus a decent thermostat, or a zoo med reptibator which already has the decent thermostat. The total should run you about $150 either way. People do use homemade incubators but it can be more difficult to keep the heat even.