I bought mine sometime ago now the pricing being approx £150. Main things to look out for IMHO is that if you buy one that doesn't have wheels, it will not stand upright and, due to a concave bottom, is unstable. It is a good idea to make a stand for it and then level the pot.
Also always loosen and tighten the bolts in the same order and always mount the lid in the same orientation. This forms the seal to the pot rim. Also there is no need to over tighten the bolts. All that happens there is you crush the seal even though mine came with a socking great spanner!!!
Just my penny's (pennies?) worth.