Here's the thing. Say each female produces 8 eggs. You could pair your banana spider to the spider, statistically you get Normal, banana, 2x spider, 2x banana spider, super spider, super spider banana. Which statistically leaves you with 6 healthy snakes. A banana spider to a normal statistically gives you 2x normal, 2x banana, 2x spider, 2x banana spider.
So really you only cutting yourself out a banana and a normal doing that pairing, but if you have the possibility, it would be much better to breed the spider female to another male and breed the banana spider to another non-spider female, giving you much better odds at hitting the snakes you might want to produce.
I don't see anything unresponsible about doing the pairing, the market is flooded with sub 200 dollar animals, no harm in producing less animals if it still meets your goals