Always remember price depends on how available the fish are in your area, and what you're willing to spend.
You said you 'finally' found something other than senegalus, so that tells me bichirs are hard to come by. If that's the case, and you're willing to drop $100 on a couple fish, then it sounds very worth the price. You can always try to haggle politely and if they wont drop then just give them what they're asking.