First of all, I hate that they actually put that "armour" on the guinea pig.
Even if it's just for a shoot. It's alot of metal and weight for a little critter.
Now on to the costs (Of course the amount it was sold for is ridiculous):
The scale-mail is made from polished steel scales and steel rings. It was painstakingly "woven" by me over several weeks in an effort to better prepare my guinea pig Lucky for the dangers of the modern world. The helmet was purchased at a Renaissance Faire later as it was the perfect finishing touch.
Miniature helmets of that kind you can get for about 30€.
The scales, they seem to be made of run-of-the-mill mediocre steel, no idea about the maille rings.
On a sidenote, it's completely and utterly stupid to weave scale armour with maille rings.
Scale protects better than maille in every way possible, so "weaving" it with maille adds an extreme amount of useless weight.
It would have been much less work if the person who made this "armour" just used leather lacing like in historical originals, or had just sewn them with strong thread.
Overall, it's a "collectors item", but with the uncertain quality of the actual materials used and the pointless use of maille rings to connect the scales, I really wouldn't consider it to be worth more than 150 - 200 €, and that's being generous due to "weaving" the scales IS quite a bit of work.
For a "real" scale shirt, modern replica, combat ready... well I'd say about 620€ will get you a decent one.
If you're willing to go for Eastern European budget quality, you might get one for about 400€.
Never been interested in scale though, so that's just a quick estimate considering the average prices of scale on markets that produce armour that can be used in combat and isn't -utter- crap.