1867 Russian 125 rubles bond

Found this at the local charity shop - is £30 a good deal for this item?

(I’ve edited the brightness and saturation in the photo to obscure my face so it’s not actually that bright)

a quick google search showed a very similar bond in slightly worse condition had sold for £10 on eBay, but two (an 1867 and 1869 in worse condition) are set to go under the hammer with Spink and have a value estimate of $100-$150 US.

I’m not very experienced with bonds, so I have no idea what the value would be. I also have no idea how to spot fakes/replicas.

Should I buy?

Your research suggests that this is great bargain.
Likewise I am not sure how to confirm if it is indeed a replica.

Everything is right. It depends on what to compare and where. And, by the way, where are the coupons? They also have cut-off coupons attached...
This one in the photo-3.5 pounds, well, a little worse than Yours-is sold, but with coupons-8.5 pounds and there are no takers...