Average price for a Inspector / Snowball Pleco...

Was in the LFS today and saw waht I thought was a vampire pleco or snowball pleco, then when I asked the manager he said ohh...
that is the Inspector pleco and we want £25 for it.

Then I got home checked it out online and then realised the Snowball pleco and been renamed Inspector lol...

So now I got that clear in my head hpow much would you guys n gals say one would be worth?

thanks in advance...