You know you have a knife that's truly for you when everything about it just feels right to you.
The Rift is worth more than the Para 2, so as long as the Rift was used but taken care of(not beat to the point where it doesn't function right or not beat to hell) I'm sure someone would trade a Para 2 for it. Better yet you could trade your well used Rift for a Used Para 2 in good condition and use it. Just because a knife is used, doesn't mean it doesn't have value. And just because it's used, doesn't mean it can't be used for a very long time.
If you really like the Rift and enjoy it, carry it a couple of times, see if you want to carry and use it. If not, put it back in it's box or wherever you store your knives.
The Para 2 is a great knife and I'm sure you'll pick one up eventually. But see if you want to use the Rift, and if you do, you're not really hurting anything by using it. And if you decide you want to trade it for a Para 2, keep in mind the value of knives, and trading for a used knife is not a bad thing. I prefer my knives to be used actually. Just not beat to hell and back. As long as the knife still looks okay and is functionally sound, I'm good to go. =]