75k to 100k is insane. Dunno if you can scam some newb into paying that (if you can than by all means do so). The statistics on minipet probability and price are both available on these forums. Just do the math for the intrinisic value of each present (probabilistic minipet value) and sell if you can get someone to buy for more and open if you cannot.
I'm thinking if you can sell for 50k+, you're going to come out on top. I can pretty much find most of the common minipets for 15-20k despite it being listed higher in sticky.