Usually, when it comes to these kinds of upgrades, I either do one of two things. If the two consoles can play together, I usually will keep the second. With Nintendo consoles, I will keep one and sit on it (usually until the next generation) and then mod it.

Or alternatively I’ll once in a blue moon, sell it to someone else for a fair price. It can help offset the cost of the new thing, and you know that your old device is still going to get used by someone else who can appreciate it.