Best I can tell. Tho, not specifically your blade steels..
At auction, 88-160$ (higher have scales and sheaths)..
88$ was the only one under 100$..
Most range in the 120-130$..
So on average.. 125$.. (at auction)..
Not saying they may not sell at 150$.. K390 and 4V are higher on mosts, wanted list..
Sorry but sales prices for Spyderco Mules are currently much higher than this.
If you do a search of past sales on EB (something that would be nice to also have on BF), you'll find that most Mules are going from between $130-300 with most sales in the $175-250 range for just the blade alone (plus tax & shipping which actually increases the cost to the buyer to around $200-275 if purchased there).
The cost of a pair of Halpern scales and a Spyderco sheath would add at at least another $90, if you buy them yourself ($60 for the scales and $30 for the sheaths), but are usually discounted by 50% in a 2ndary sale which includes them w/the blade,
Better deals can be had w/the right timing but realistically, in the current market, you should expect to pay at least $175-250 (plus tax & shipping costs, if any) for any of the Mules the OP is asking about, which is about 3-5x's the release price of $50.
Consider yourself fortunate if you can do better than that.
I just purchased a S45VN Mule off of the BF Exchange for just $100 but, of course, that's still 2x the original release price. Add a pair of Halpern scales and the total cost of that blade to me was $160.
I also just purchased a ZMax Mule on EB for $169 (over 3xs the release price) plus tax for a total of $183.79 (shipping included). Add a pair of Halpern scales to that blade and the total was about $245.
I definitely consider myself "lucky" to have seen the ads for these Mules when I did in order to purchase them for these prices. If I didn't see them 1st, someone else surely would have bought them instead.
BTW, if you don't get one of the MagnaCut Mules for the release price of $75 from Spyderco in a few days, I'll be very surprised if the asking prices for them in the 2ndary market does not exceed $300 (about 4x the release price).