first idea i had is enchi yellowbelly, because ivorys are always cool to hatch out, and its possible to tell apart enchi ivory from ivory. i dont know if you can see spider in ivorys, but then, you only get 25% ivory combos anyway, and enchi ivory is really awesome for future breeding down the road.

but with a 500 dollar budget, you might have to settle for a single-gene enchi female or some basic enchi combo like pastel enchi. im biased, i absolutely love enchi, and i dont really like pastel. something like lesser fire or black pastel fire would also be neat. if you want to go for combos in the ivory / super stripe / puma / highway complex further down the road, i think adding enchi sooner rather than later should have a high priority.