Aw, ****. Here we go again with the TT/Dupe discourse.
In all honesty and if you wish to know why:
Amiibo/campsite villager glitch makes it hard to trade villagers and in
my very honest opinion, they have the right to charge that high because cycling villagers is very RNG with TTing that I could take 30 minutes if I'm lucky or 5 hours if I'm not lucky. You're paying the time someone invested on getting the villager you need to get out (of course, not applicable to cycling shops as they go "my pace" route).
Raymond is a given because you can't summon him willynilly (via Amiibo) like every villagers (he's new and has nicer design). Marshal is merely a 100NMT but Raymond is subjective and dependent on the seller's personality. (Some wants to hardcap it to a cheaper price, some leaves it openended so the prices skyrocket.) Supply and demand has been like this since the beginning of time.
However, I do detest people selling him for IRL money. I know times are hard right now but this is borderline exploitative and illegal.
In Japan, he's selling for 20,000 yen. It's ridiculous. (and I'm sure it's a savestated Raymond because they're selling more than one LOL...)
I suggest you just have to wait and see the Earth Day update if they fix the Amiibo glitch. Prices should be cheaper once it's fixed as people can massproduce villagers to sell and oversaturate the market to the point of Tier 5 villager prices.